diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 20f81ca7..1ae39b56 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -25,7 +25,7 @@ jobs:
 
         strategy:
             matrix:
-                node-version: [20.x, 22.x, 24.x] # Define a matrix of Node.js versions to test
+                node-version: [22.x, 24.x, 26.x] # Define a matrix of Node.js versions to test
 
         steps:
             - name: Checkout code
diff --git a/api/.eslintrc b/api/.eslintrc
index 1f8f0d4b..c2cd7e68 100644
--- a/api/.eslintrc
+++ b/api/.eslintrc
@@ -34,7 +34,15 @@
                 "import/extensions": ["off"],
                 "no-shadow": ["off"],
                 "@typescript-eslint/no-shadow": ["error"],
-                "no-console": "warn"
+                "no-console": "warn",
+                "no-unused-vars": "off",
+                "@typescript-eslint/no-unused-vars": [
+                    "error",
+                    {
+                        "argsIgnorePattern": "^_",
+                        "varsIgnorePattern": "^_"
+                    }
+                ]
             }
         }
     ]
diff --git a/api/docker-compose.yml b/api/docker-compose.yml
index a2089299..d83a89c3 100644
--- a/api/docker-compose.yml
+++ b/api/docker-compose.yml
@@ -1,6 +1,6 @@
 services:
   postgres:
-    image: postgres:13
+    image: postgres:14
     ports:
       - '5432:5432'
     environment:
diff --git a/api/docs/breaking-changes.md b/api/docs/breaking-changes.md
new file mode 100644
index 00000000..e9722671
--- /dev/null
+++ b/api/docs/breaking-changes.md
@@ -0,0 +1,78 @@
+# Teams Refactor Breaking Changes
+
+This release changes the room WebSocket protocol from player-owned state to
+team-owned state. Third-party clients must update their room state models before
+connecting to rooms running this API version.
+
+## Player Lists
+
+The `players` field on `connected`, `chat`, `cellUpdate`, `syncBoard`, and other
+room messages is no longer an array of players. It is now an object with two
+arrays:
+
+```ts
+{
+    teams: Team[];
+    spectators: Player[];
+}
+```
+
+Players in `teams` are nested under their team. Spectators are listed only in
+`spectators`. Each `Player` now has `teamId`, which is an empty string for a
+spectator.
+
+## Teams And Colors
+
+`Team` is a new protocol type with `id`, `name`, `color`, `goalCount`, and
+`players`. `Team.color` is the authoritative mark color.
+
+`Player.color` has been removed from the API payload. Clients must read colors
+from the containing team and must not render a color for spectators.
+
+The existing `changeColor` action now changes the authenticated player's team
+color. Spectators cannot use it.
+
+## Board Cells
+
+`completedPlayers` has been renamed to `completedTeams`. The array contains
+team IDs rather than player IDs. Use each ID to resolve a team from
+`players.teams`, then use that team's `color` when rendering a completed cell.
+
+## Teams Setting
+
+`RoomData` now includes required boolean `teamsEnabled`. It is included in the
+initial room response and `updateRoomData` messages.
+
+When `teamsEnabled` is `false`, the API still creates one internal team per
+player to own marks, but messages display player names and joining another team
+is forbidden. When it is `true`, messages display team names and players may
+join existing teams.
+
+Monitors can update the setting over WebSocket:
+
+```json
+{
+    "action": "setTeamsEnabled",
+    "payload": { "enabled": true },
+    "authToken": "<room token>"
+}
+```
+
+Clients should update local room state after the resulting `updateRoomData`
+message.
+
+## New Action
+
+`joinTeam` is available when teams are enabled:
+
+```json
+{
+    "action": "joinTeam",
+    "payload": { "teamId": "<team id>" },
+    "authToken": "<room token>"
+}
+```
+
+Clients must handle `joinedTeam`, which returns the destination `Team`, and
+`forbidden`, which is returned when teams are disabled or the token lacks the
+necessary permission.
\ No newline at end of file
diff --git a/api/docs/testing-plan.md b/api/docs/testing-plan.md
new file mode 100644
index 00000000..484d24f0
--- /dev/null
+++ b/api/docs/testing-plan.md
@@ -0,0 +1,241 @@
+# Test Coverage Analysis & Improvement Plan
+
+> **Date:** July 2026  
+> **Status:** Proposal  
+> **Location:** tests
+
+## Summary
+
+Our existing test suite covers board generation, utility functions, and basic user registration, but large areas of the codebase remain completely untested — particularly API routes, database operations, Room logic (mark/unmark/join/leave/win conditions), authentication, WebSocket handling, and race integration.
+
+This document outlines what's currently tested, what's missing, and a phased plan to add both unit tests and integration tests backed by a real PostgreSQL database.
+
+---
+
+## What's Currently Tested
+
+| Test File | What It Tests |
+|-----------|---------------|
+| `createUser.test.ts` | Registration endpoint — auth token validation, user creation (mocked DB) |
+| `GoalValidation.test.ts` | `validateGoalMeta()` — byte limits, prototype pollution, circular refs, depth bombs |
+| `core/boardGenerator.test.ts` | Full board generation pipeline — filters, layouts (random/SRLv5/static), restrictions, determinism |
+| `core/Cleanup.test.ts` | Room inactivity detection, `canClose()`, cleanup timer |
+| `core/TeamPlayer.test.ts` | Team goal marking/unmarking with BigInt bitmasks, exploration cell reveals |
+| `util/Array.test.ts` | Seeded `shuffle()` function |
+| `util/WinDetection.test.ts` | `computeLineMasks()` and `hasLineCompletion()` for variable board sizes |
+
+**What works well:** Board generation is thoroughly tested. Utility functions have solid coverage. The test setup provides a reusable auth mock pattern.
+
+**What's weak:** All DB interactions are mocked — we have no confidence the actual queries work. Only 1 out of ~15 route files has any test coverage. Core Room logic (the largest file) is barely tested beyond cleanup.
+
+---
+
+## Gaps — Unit Tests Needed
+
+### Priority 1: Core Game Logic
+
+**`core/Room.ts`** (~1200 lines, barely tested)
+
+| Method | What to Test |
+|--------|-------------|
+| `handleMark` / `handleUnmark` | Cell state changes, broadcast to all players, permission enforcement |
+| `handleJoin` / `handleSocketClose` | Player tracking, team assignment, reconnection |
+| `handleChat` | Message broadcasting, chat-disabled enforcement |
+| `handleNewCard` | Board re-generation, state clearing |
+| `checkWinConditions` | All three modes: LOCKOUT, LINES, BLACKOUT |
+| `canAutoAuthenticate` | Staff/moderator detection |
+
+**`auth/RoomAuth.ts`**
+
+| Function | What to Test |
+|----------|-------------|
+| `createRoomToken()` | Produces valid JWT, correct payload fields (roomSlug, playerId, permissions) |
+| `verifyRoomToken()` | Rejects invalid/expired/wrong-room tokens; accepts valid |
+| `invalidateToken()` | Token rejected after invalidation |
+| `hasPermission()` | Spectators can't mark/unmark, only monitors can newCard, etc. |
+
+### Priority 2: Authentication & Users
+
+**`lib/Auth.ts`**
+- `validatePassword()` — correct password → true, wrong → false
+- `validateUsernamePasswordCombo()` — same, by username
+- `hashPassword()` determinism
+
+**`util/Session.ts`**
+- `removeSessionsForUser()` — finds and removes all sessions for a user
+
+### Priority 3: API Routes (only Registration has a test)
+
+| Route File | Endpoints to Test |
+|-----------|-------------------|
+| `auth/Auth.ts` | Login, logout, session validation |
+| `games/Games.ts` | CRUD games |
+| `games/Variants.ts` | CRUD variants |
+| `goals/Goals.ts` | CRUD goals |
+| `goals/GoalCategories.ts` | Category management |
+| `goals/Upload.ts` | Bulk goal upload/import |
+| `rooms/Rooms.ts` | Room creation, listing |
+| `rooms/actions/Actions.ts` | Room action dispatching |
+| `users/Users.ts` | User profile retrieval/update |
+| `oauth/OAuth.ts` | OAuth flow |
+| middleware.ts | `requiresApiToken` — valid/invalid/missing token |
+
+### Priority 4: Supporting Modules
+
+| Module | What to Test |
+|--------|-------------|
+| `core/RoomServer.ts` | WebSocket token verification, 60s auth timeout, message routing, ping/keepalive |
+| `core/integration/races/LocalTimer.ts` | Timer start/stop/reset |
+| `core/integration/races/RacetimeHandler.ts` | Racetime.gg WebSocket integration (mock external WS) |
+| `communication/outgoing/Email.ts` | Template rendering, transport mocking |
+| `media/MediaServer.ts` | Avatar upload validation, file type/size checks |
+
+---
+
+## Integration Tests — New Test Suite
+
+### Why?
+
+All existing tests mock the database. This means:
+- **Zero confidence** that Prisma queries actually work against PostgreSQL
+- Schema migrations could break queries without any test catching it
+- Complex queries with joins, filters, and relations are completely untested
+
+### Architecture
+
+```
+┌─────────────────────────────────────────────┐
+│  jest.integration.config.ts                 │
+│  (separate config, *.integration.test.ts)   │
+├─────────────────────────────────────────────┤
+│  Global Setup                               │
+│  - Create test database (bingogg_test)      │
+│  - Run prisma migrate deploy                │
+│  - Optionally seed reference data           │
+├─────────────────────────────────────────────┤
+│  Test Execution                             │
+│  - Real Prisma client → real PostgreSQL     │
+│  - cleanDatabase() between test files       │
+├─────────────────────────────────────────────┤
+│  Global Teardown                            │
+│  - Drop test database                       │
+└─────────────────────────────────────────────┘
+         │
+         ▼
+┌─────────────────────────────────────────────┐
+│  Docker Compose (already exists)            │
+│  PostgreSQL 14 on port 5432                 │
+└─────────────────────────────────────────────┘
+```
+
+### Phase 1: Test Infrastructure
+
+1. **Create `jest.integration.config.ts`** — separate Jest config targeting `**/*.integration.test.ts` with longer timeouts (30s)
+2. **Create `src/tests/integration/setup.ts`** — global setup that creates `bingogg_test` database, runs `prisma migrate deploy`, exports `cleanDatabase()` helper
+3. **Create `src/tests/integration/teardown.ts`** — drops the test database
+4. **Add npm script:**
+   ```json
+   "test:integration": "DATABASE_URL=postgresql://postgres:password@localhost:5432/bingogg_test jest --config jest.integration.config.ts --forceExit --runInBand"
+   ```
+
+### Phase 2: Database Layer Tests
+
+| Test File | Functions to Cover |
+|-----------|-------------------|
+| `database/Users.integration.test.ts` | `registerUser`, `userByEmail`, `userByUsername`, `emailUsed`, `usernameUsed`, `getUser` |
+| `database/Rooms.integration.test.ts` | `createRoom`, `addJoinAction`, `addMarkAction`, `setRoomBoard`, `getFullRoomList` |
+| `database/games/Games.integration.test.ts` | Full CRUD for games |
+| `database/games/Goals.integration.test.ts` | CRUD goals, category/tag associations, filtering |
+| `database/auth/ApiTokens.integration.test.ts` | Token creation, `validateToken`, revocation |
+
+### Phase 3: Route Integration Tests (HTTP + Real DB)
+
+Use `supertest` with the real Express app + real database:
+
+| Test File | Flow to Test |
+|-----------|-------------|
+| `routes/registration.integration.test.ts` | Full registration → verify user in DB |
+| `routes/auth.integration.test.ts` | Register → login → session cookie → authenticated request → logout |
+| `routes/games.integration.test.ts` | Create game → list → get → update → delete |
+| `routes/goals.integration.test.ts` | Create goal → assign categories/tags → filter → delete |
+| `routes/rooms.integration.test.ts` | Create room → list → verify DB entry |
+
+### Phase 4: WebSocket Integration Tests (can defer)
+
+- Use the `ws` library as a test client
+- Full lifecycle: connect → authenticate → join room → mark cell → verify state → detect win → disconnect
+
+### Cleanup Strategy
+
+Truncate all tables between test files:
+
+```typescript
+export async function cleanDatabase() {
+  const tablenames = await prisma.$queryRaw<{ tablename: string }[]>`
+    SELECT tablename FROM pg_tables WHERE schemaname='public'
+  `;
+  for (const { tablename } of tablenames) {
+    if (tablename !== '_prisma_migrations') {
+      await prisma.$executeRawUnsafe(`TRUNCATE TABLE "public"."${tablename}" CASCADE;`);
+    }
+  }
+}
+```
+
+---
+
+## Suggested First Contributions
+
+| Task | Difficulty | Impact |
+|------|-----------|--------|
+| Unit tests for `auth/RoomAuth.ts` | Easy | High — critical auth path |
+| Unit tests for `hasPermission()` | Easy | High — security-relevant |
+| Integration test infrastructure (Phase 1) | Medium | High — unblocks all integration work |
+| Unit tests for `Room.checkWinConditions` | Medium | High — core game logic |
+| Database integration tests for Users | Easy | Medium — template for other DB tests |
+| Route tests for middleware.ts | Easy | Medium — auth boundary |
+| Unit tests for `core/Room.handleMark` | Hard | High — complex state management |
+
+---
+
+## CI Integration
+
+```yaml
+- name: Start test database
+  run: docker compose up -d
+
+- name: Wait for PostgreSQL
+  run: until pg_isready -h localhost -p 5432; do sleep 1; done
+
+- name: Run unit tests
+  run: npm test
+
+- name: Run integration tests
+  run: npm run test:integration
+  env:
+    DATABASE_URL: postgresql://postgres:password@localhost:5432/bingogg_test
+
+- name: Stop test database
+  run: docker compose down
+```
+
+---
+
+## Coverage Targets
+
+| Module | Current (est.) | Target |
+|--------|----------------|--------|
+| `core/` | ~30% | >70% |
+| `database/` | 0% | >80% |
+| `routes/` | ~5% | >60% |
+| `auth/` | 0% | >90% |
+| `util/` | ~60% | >90% |
+| `lib/` | 0% | >80% |
+
+---
+
+## Open Questions
+
+1. **Test DB seeding** — Should integration tests use `prisma db seed` for baseline reference data, or create all needed data in each test?
+2. **CI environment** — Does CI already have Docker available, or do we need a service container?
+3. **WebSocket tests** — Should we defer Phase 4 until Phases 1-3 are solid?
\ No newline at end of file
diff --git a/api/package-lock.json b/api/package-lock.json
index 79f27613..b332ab89 100644
--- a/api/package-lock.json
+++ b/api/package-lock.json
@@ -870,6 +870,7 @@
             "integrity": "sha512-H3mcG6ZDLTlYfaSNi0iOKkigqMFvkTKlGUYlD8GW7nNOYRrevuA46iTypPyv+06V3fEmvvazfntkBU34L0azAw==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@babel/code-frame": "^7.28.6",
                 "@babel/generator": "^7.28.6",
@@ -3683,6 +3684,7 @@
             "integrity": "sha512-b63wmnKPaK+6ZZfpYhz9K61oybvbI1aMcIs80++JI1O1rR1vaxHUCNqo3ITu6NU0d4V34yZFoHMn/uoKr/Rwfw==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@jest/environment": "30.2.0",
                 "@jest/expect": "30.2.0",
@@ -4013,6 +4015,7 @@
             "resolved": "https://registry.npmjs.org/@opentelemetry/api/-/api-1.9.0.tgz",
             "integrity": "sha512-3giAOQvZiH5F9bMlMiv8+GSPMeqg0dbaeo58/0SlA9sxSqZhnUtxzX9/2FzyhS9sWQf5S0GJE0AKBrFqjpeYcg==",
             "license": "Apache-2.0",
+            "peer": true,
             "engines": {
                 "node": ">=8.0.0"
             }
@@ -4252,6 +4255,7 @@
             "integrity": "sha512-gR2EMvfK/aTxsuooaDA32D8v+us/8AAet+C3J1cc04SW35FPdZYgLF+iN4NDLUgAaUGTKdAB0CYenu1TAgGdMg==",
             "hasInstallScript": true,
             "license": "Apache-2.0",
+            "peer": true,
             "engines": {
                 "node": ">=18.18"
             },
@@ -5539,6 +5543,7 @@
             "resolved": "https://registry.npmjs.org/@types/node/-/node-25.0.9.tgz",
             "integrity": "sha512-/rpCXHlCWeqClNBwUhDcusJxXYDjZTyE8v5oTO7WbL8eij2nKhUeU89/6xgjU7N4/Vh3He0BtyhJdQbDyhiXAw==",
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "undici-types": "~7.16.0"
             }
@@ -5712,6 +5717,7 @@
             "integrity": "sha512-npiaib8XzbjtzS2N4HlqPvlpxpmZ14FjSJrteZpPxGUaYPlvhzlzUZ4mZyABo0EFrOWnvyd0Xxroq//hKhtAWg==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@typescript-eslint/scope-manager": "8.53.0",
                 "@typescript-eslint/types": "8.53.0",
@@ -6230,6 +6236,7 @@
             "integrity": "sha512-NZyJarBfL7nWwIq+FDL6Zp/yHEhePMNnnJ0y3qfieCrmNvYct8uvtiV41UvlSe6apAfk0fY1FbWx+NwfmpvtTg==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "bin": {
                 "acorn": "bin/acorn"
             },
@@ -6275,6 +6282,7 @@
             "resolved": "https://registry.npmjs.org/@redocly/ajv/-/ajv-8.17.1.tgz",
             "integrity": "sha512-EDtsGZS964mf9zAUXAl9Ew16eYbeyAFWhsPr0fX6oaJxgd8rApYlPBf0joyhnUHz88WxrigyFtTaqqzXNzPgqw==",
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "fast-deep-equal": "^3.1.3",
                 "fast-uri": "^3.0.1",
@@ -6881,6 +6889,7 @@
                 }
             ],
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "baseline-browser-mapping": "^2.9.0",
                 "caniuse-lite": "^1.0.30001759",
@@ -8245,6 +8254,7 @@
             "integrity": "sha512-LEyamqS7W5HB3ujJyvi0HQK/dtVINZvd5mAAp9eT5S/ujByGjiZLCzPcHVzuXbpJDJF/cxwHlfceVUDZ2lnSTw==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@eslint-community/eslint-utils": "^4.8.0",
                 "@eslint-community/regexpp": "^4.12.1",
@@ -8431,6 +8441,7 @@
             "integrity": "sha512-whOE1HFo/qJDyX4SnXzP4N6zOWn79WhnCUY/iDR0mPfQZO8wcYE4JClzI2oZrhBnnMUCBCHZhO6VQyoBU95mZA==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@rtsao/scc": "^1.1.0",
                 "array-includes": "^3.1.9",
@@ -8915,7 +8926,6 @@
             "resolved": "https://registry.npmjs.org/express-handlebars/-/express-handlebars-8.0.4.tgz",
             "integrity": "sha512-1mXd9jxLfZgFjpPGamAizVhwukvwLlXRV0dPcsEvW2hqUlYICMtJAQrqFSmgwHFvbVeIA/afPOtmHtNF516pmQ==",
             "license": "BSD-3-Clause",
-            "peer": true,
             "dependencies": {
                 "glob": "^12.0.0",
                 "graceful-fs": "^4.2.11",
@@ -8930,7 +8940,6 @@
             "resolved": "https://registry.npmjs.org/balanced-match/-/balanced-match-4.0.4.tgz",
             "integrity": "sha512-BLrgEcRTwX2o6gGxGOCNyMvGSp35YofuYzw9h1IMTRmKqttAZZVU67bdb9Pr2vUHA8+j3i2tJfjO6C6+4myGTA==",
             "license": "MIT",
-            "peer": true,
             "engines": {
                 "node": "18 || 20 || >=22"
             }
@@ -8940,7 +8949,6 @@
             "resolved": "https://registry.npmjs.org/brace-expansion/-/brace-expansion-5.0.4.tgz",
             "integrity": "sha512-h+DEnpVvxmfVefa4jFbCf5HdH5YMDXRsmKflpf1pILZWRFlTbJpxeU55nJl4Smt5HQaGzg1o6RHFPJaOqnmBDg==",
             "license": "MIT",
-            "peer": true,
             "dependencies": {
                 "balanced-match": "^4.0.2"
             },
@@ -8953,7 +8961,6 @@
             "resolved": "https://registry.npmjs.org/glob/-/glob-12.0.0.tgz",
             "integrity": "sha512-5Qcll1z7IKgHr5g485ePDdHcNQY0k2dtv/bjYy0iuyGxQw2qSOiiXUXJ+AYQpg3HNoUMHqAruX478Jeev7UULw==",
             "license": "BlueOak-1.0.0",
-            "peer": true,
             "dependencies": {
                 "foreground-child": "^3.3.1",
                 "jackspeak": "^4.1.1",
@@ -8977,7 +8984,6 @@
             "resolved": "https://registry.npmjs.org/minimatch/-/minimatch-10.2.4.tgz",
             "integrity": "sha512-oRjTw/97aTBN0RHbYCdtF1MQfvusSIBQM0IZEgzl6426+8jSC0nF1a/GmnVLpfB9yyr6g6FTqWqiZVbxrtaCIg==",
             "license": "BlueOak-1.0.0",
-            "peer": true,
             "dependencies": {
                 "brace-expansion": "^5.0.2"
             },
@@ -10641,6 +10647,7 @@
             "integrity": "sha512-F26gjC0yWN8uAA5m5Ss8ZQf5nDHWGlN/xWZIh8S5SRbsEKBovwZhxGd6LJlbZYxBgCYOtreSUyb8hpXyGC5O4A==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@jest/core": "30.2.0",
                 "@jest/types": "30.2.0",
@@ -12069,6 +12076,7 @@
             "resolved": "https://registry.npmjs.org/mobx/-/mobx-6.15.0.tgz",
             "integrity": "sha512-UczzB+0nnwGotYSgllfARAqWCJ5e/skuV2K/l+Zyck/H6pJIhLXuBnz+6vn2i211o7DtbE78HQtsYEKICHGI+g==",
             "license": "MIT",
+            "peer": true,
             "funding": {
                 "type": "opencollective",
                 "url": "https://opencollective.com/mobx"
@@ -12298,6 +12306,7 @@
             "resolved": "https://registry.npmjs.org/nodemailer/-/nodemailer-7.0.12.tgz",
             "integrity": "sha512-H+rnK5bX2Pi/6ms3sN4/jRQvYSMltV6vqup/0SFOrxYYY/qoNvhXPlYq3e+Pm9RFJRwrMGbMIwi81M4dxpomhA==",
             "license": "MIT-0",
+            "peer": true,
             "engines": {
                 "node": ">=6.0.0"
             }
@@ -13086,6 +13095,7 @@
             "integrity": "sha512-++ZJ0ijLrDJF6hNB4t4uxg2br3fC4H9Yc9tcbjr2fcNFP3rh/SBNrAgjhsqBU4Ght8JPrVofG/ZkXfnSfnYsFg==",
             "hasInstallScript": true,
             "license": "Apache-2.0",
+            "peer": true,
             "dependencies": {
                 "@prisma/config": "6.19.3",
                 "@prisma/engines": "6.19.3"
@@ -13386,6 +13396,7 @@
             "resolved": "https://registry.npmjs.org/react/-/react-19.2.3.tgz",
             "integrity": "sha512-Ku/hhYbVjOQnXDZFv2+RibmLFGwFdeeKHFcOTlrt7xplBnya5OGn/hIRDsqDiSUcfORsDC7MPxwork8jBwsIWA==",
             "license": "MIT",
+            "peer": true,
             "engines": {
                 "node": ">=0.10.0"
             }
@@ -13395,6 +13406,7 @@
             "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-19.2.3.tgz",
             "integrity": "sha512-yELu4WmLPw5Mr/lmeEpox5rw3RETacE++JgHqQzd2dg+YbJuat3jH4ingc+WPZhxaoFzdv9y33G+F7Nl5O0GBg==",
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "scheduler": "^0.27.0"
             },
@@ -14625,6 +14637,7 @@
             "resolved": "https://registry.npmjs.org/styled-components/-/styled-components-6.3.8.tgz",
             "integrity": "sha512-Kq/W41AKQloOqKM39zfaMdJ4BcYDw/N5CIq4/GTI0YjU6pKcZ1KKhk6b4du0a+6RA9pIfOP/eu94Ge7cu+PDCA==",
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@emotion/is-prop-valid": "1.4.0",
                 "@emotion/unitless": "0.10.0",
@@ -15062,6 +15075,7 @@
             "integrity": "sha512-f0FFpIdcHgn8zcPSbf1dRevwt047YMnaiJM3u2w2RewrB+fob/zePZcrOyQoLMMO7aBIddLcQIEK5dYjkLnGrQ==",
             "dev": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@cspotcode/source-map-support": "^0.8.0",
                 "@tsconfig/node10": "^1.0.7",
@@ -15329,6 +15343,7 @@
             "resolved": "https://registry.npmjs.org/typescript/-/typescript-5.9.3.tgz",
             "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
             "license": "Apache-2.0",
+            "peer": true,
             "bin": {
                 "tsc": "bin/tsc",
                 "tsserver": "bin/tsserver"
@@ -15465,6 +15480,7 @@
             "dev": true,
             "hasInstallScript": true,
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "napi-postinstall": "^0.3.0"
             },
@@ -15721,6 +15737,7 @@
             "resolved": "https://registry.npmjs.org/winston/-/winston-3.19.0.tgz",
             "integrity": "sha512-LZNJgPzfKR+/J3cHkxcpHKpKKvGfDZVPS4hfJCc4cCG0CgYzvlD6yE/S3CIL/Yt91ak327YCpiF/0MyeZHEHKA==",
             "license": "MIT",
+            "peer": true,
             "dependencies": {
                 "@colors/colors": "^1.6.0",
                 "@dabh/diagnostics": "^2.0.8",
diff --git a/api/package.json b/api/package.json
index d538a40b..5ea2c496 100644
--- a/api/package.json
+++ b/api/package.json
@@ -10,8 +10,8 @@
         "dev": "tsc-watch --noClear --onSuccess \"node build/src/main.js\"",
         "build": "tsc --sourceMap false",
         "db:reset": "prisma migrate reset",
-        "db:pre-migrate": "npm run db:update-defaults && prisma migrate dev",
-        "db:migrate": "npm run db:pre-migrate && prisma migrate dev",
+        "db:pre-migrate": "npm run db:update-defaults && prisma migrate deploy",
+        "db:migrate": "npm run db:pre-migrate && prisma migrate deploy",
         "db:seed": "prisma db seed",
         "db:generate-client": "prisma generate",
         "db:update-defaults": "tsx scripts/update-prisma-defaults.ts",
diff --git a/api/prisma/migrations/20260515200019_refactor_for_teams/data-migration.ts b/api/prisma/migrations/20260515200019_refactor_for_teams/data-migration.ts
new file mode 100644
index 00000000..dd4940b7
--- /dev/null
+++ b/api/prisma/migrations/20260515200019_refactor_for_teams/data-migration.ts
@@ -0,0 +1,45 @@
+import { PrismaClient } from '@prisma/client';
+
+const prisma = new PrismaClient();
+
+async function main() {
+    await prisma.$transaction(
+        async (tx) => {
+            // Player.spectator is deprecated but retained for this migration.
+            // Player.color is also retained in the database but is no longer used.
+            const players = await tx.player.findMany({
+                select: {
+                    id: true,
+                    spectator: true,
+                    roomId: true,
+                    nickname: true,
+                },
+            });
+
+            for (const player of players) {
+                if (!player.spectator) {
+                    const team = await tx.team.create({
+                        data: {
+                            name: `${player.nickname}'s Team`,
+                            key: player.id,
+                            roomId: player.roomId,
+                        },
+                    });
+
+                    await tx.player.update({
+                        where: { id: player.id },
+                        data: { teamId: team.id },
+                    });
+                }
+            }
+        },
+        { timeout: 300000 },
+    );
+}
+
+main()
+    .catch(async (e) => {
+        console.error(e);
+        process.exit(1);
+    })
+    .finally(async () => await prisma.$disconnect());
diff --git a/api/prisma/migrations/20260515200019_refactor_for_teams/migration.sql b/api/prisma/migrations/20260515200019_refactor_for_teams/migration.sql
new file mode 100644
index 00000000..9ac5f2c9
--- /dev/null
+++ b/api/prisma/migrations/20260515200019_refactor_for_teams/migration.sql
@@ -0,0 +1,26 @@
+-- AlterTable
+-- Legacy Player.color and Player.spectator data are retained for a later migration.
+ALTER TABLE "Player" ADD COLUMN "teamId" TEXT;
+
+-- AlterTable
+ALTER TABLE "Room" ADD COLUMN "teamsEnabled" BOOLEAN NOT NULL DEFAULT false;
+
+-- CreateTable
+CREATE TABLE "Team" (
+    "id" TEXT NOT NULL,
+    "key" TEXT NOT NULL,
+    "name" TEXT NOT NULL,
+    "color" TEXT NOT NULL DEFAULT 'blue',
+    "roomId" TEXT NOT NULL,
+
+    CONSTRAINT "Team_pkey" PRIMARY KEY ("id")
+);
+
+-- CreateIndex
+CREATE UNIQUE INDEX "Team_id_key" ON "Team"("id");
+
+-- AddForeignKey
+ALTER TABLE "Team" ADD CONSTRAINT "Team_roomId_fkey" FOREIGN KEY ("roomId") REFERENCES "Room"("id") ON DELETE RESTRICT ON UPDATE CASCADE;
+
+-- AddForeignKey
+ALTER TABLE "Player" ADD CONSTRAINT "Player_teamId_fkey" FOREIGN KEY ("teamId") REFERENCES "Team"("id") ON DELETE SET NULL ON UPDATE CASCADE;
diff --git a/api/prisma/schema.prisma b/api/prisma/schema.prisma
index d3f346e1..93b3b46c 100644
--- a/api/prisma/schema.prisma
+++ b/api/prisma/schema.prisma
@@ -167,22 +167,41 @@ model Room {
   bingoMode        BingoMode    @default(LINES)
   lineCount        Int          @default(1)
   players          Player[]
+  teams            Team[]
   variant          Variant?     @relation(fields: [variantId], references: [id])
   variantId        String?
   exploration      Boolean      @default(false)
   explorationStart String?
+  teamsEnabled     Boolean      @default(false)
   raceHandler      RaceHandler?
   startedAt        DateTime?
   finishedAt       DateTime?
 }
 
+model Team {
+  id        String    @id @unique @default(cuid(2))
+  key       String
+  name      String
+  color     String    @default("blue")
+  room      Room      @relation(fields: [roomId], references: [id])
+  roomId    String
+  players   Player[]
+
+  @@unique([id, roomId])
+}
+
 model Player {
   id         String    @id @unique @default(cuid())
   key        String
   user       User?     @relation(fields: [userId], references: [id])
   room       Room      @relation(fields: [roomId], references: [id])
+  // A player either belongs to a team or is a spectator
+  team       Team?      @relation(fields: [teamId, roomId], references: [id, roomId])
+  teamId     String?
   nickname   String
+  /// @deprecated Use Team.color. Retained temporarily to preserve existing data.
   color      String    @default("blue")
+  /// @deprecated Use teamId to distinguish players from spectators. Retained temporarily for data migration compatibility.
   spectator  Boolean
   monitor    Boolean   @default(false)
   roomId     String
diff --git a/api/src/auth/RoomAuth.ts b/api/src/auth/RoomAuth.ts
index 116057ca..acf46140 100644
--- a/api/src/auth/RoomAuth.ts
+++ b/api/src/auth/RoomAuth.ts
@@ -80,6 +80,7 @@ export const hasPermission = (
         case 'resetTimer':
             return payload.isMonitor;
         case 'setChatEnabled':
+        case 'setTeamsEnabled':
             return payload.isMonitor;
         default:
             return true;
diff --git a/api/src/core/Player.ts b/api/src/core/Player.ts
index f02b9bac..ad42424f 100644
--- a/api/src/core/Player.ts
+++ b/api/src/core/Player.ts
@@ -1,14 +1,15 @@
 import {
-    HiddenCell,
     Player as PlayerClientData,
-    RevealedCell,
     ServerMessage,
+    HiddenCell,
+    RevealedCell
 } from '@playbingo/types';
 import { OPEN, WebSocket } from 'ws';
 import { RoomTokenPayload } from '../auth/RoomAuth';
-import { computeRevealedMask, rowColToMask } from '../util/RoomUtils';
 import Room from './Room';
 
+export type BoardViewProvider = () => (RevealedCell | HiddenCell)[][];
+
 /**
  * Represents a player connected to a room. While largely just a data class, this
  * class offers utilities to make keeping track of players, identities, and their
@@ -32,24 +33,11 @@ export default class Player {
     id: string;
     /** Player display name */
     nickname: string;
-    /** The players chosen color */
-    color: string;
     userId?: string;
-    /** If the player is in spectator mode or not */
-    spectator: boolean;
     /** If the player has permission to perform monitor actions in the room */
     monitor: boolean;
-
-    /** Bitset of the goals the player has marked */
-    markedGoals: bigint;
-    /** The number of goals the player has marked */
-    goalCount: number;
-    /** Whether or not the player has completed the goal of the room */
-    goalComplete: boolean;
-    linesComplete: number;
-    /** Bitset of goals that are revealed for the player in exploration based
-     * modes */
-    exploredGoals: bigint;
+    /** Parent Team Id, undefined if spectator */
+    teamId?: string;
 
     /** Open connections for the player, mapped by the id in the auth token that
      * is authorized for the connection */
@@ -57,27 +45,23 @@ export default class Player {
 
     finishedAt?: string;
 
+    getBoardView: BoardViewProvider;
+
     constructor(
         room: Room,
         id: string,
         nickname: string,
-        color: string = 'blue',
-        spectator: boolean,
         monitor: boolean,
-        userId?: string,
+        getBoardView: BoardViewProvider,
+        teamId?: string,
+        userId?: string
     ) {
         this.room = room;
         ((this.id = id), (this.nickname = nickname));
-        this.color = color;
-        this.spectator = spectator;
+        this.teamId = teamId;
         this.monitor = monitor;
         this.userId = userId;
-
-        this.markedGoals = 0n;
-        this.goalCount = 0;
-        this.goalComplete = false;
-        this.linesComplete = 0;
-        this.exploredGoals = 0n;
+        this.getBoardView = getBoardView;
 
         this.connections = new Map<string, WebSocket>();
     }
@@ -147,15 +131,13 @@ export default class Player {
         return {
             id: this.id,
             nickname: this.nickname,
-            color: this.color,
-            goalCount: this.goalCount,
+            teamId: this.teamId || '',
             raceStatus: raceUser
                 ? {
                       connected: true,
                       ...raceUser,
                   }
                 : { connected: false },
-            spectator: this.spectator,
             monitor: this.monitor,
             showInRoom: this.showInRoom(),
         };
@@ -177,19 +159,19 @@ export default class Player {
                 action: 'syncBoard',
                 board: {
                     hidden: false,
-                    board: this.obfuscateBoard(),
+                    board: this.getBoardView(),
                     width: this.room.board[0].length,
                     height: this.room.board.length,
                 },
             };
         } else if (message.action === 'syncBoard' && this.room.exploration) {
             if (!message.board.hidden) {
-                message.board.board = this.obfuscateBoard();
+                message.board.board = this.getBoardView();
             }
             finalMessage = message;
         } else if (message.action === 'connected') {
             if (!message.board.hidden) {
-                message.board.board = this.obfuscateBoard();
+                message.board.board = this.getBoardView();
             }
             finalMessage = message;
         } else {
@@ -212,86 +194,6 @@ export default class Player {
         return this.connections.size > 0;
     }
 
-    //#region Goal Tracking
-    mark(row: number, col: number) {
-        const mask = rowColToMask(row, col, this.room.board[0].length);
-        if ((this.markedGoals & mask) === 0n) {
-            this.markedGoals |= mask;
-            this.goalCount++;
-            if (this.room.exploration) {
-                this.exploredGoals = this.getRevealedMask();
-            }
-        }
-    }
-
-    unmark(row: number, col: number) {
-        const mask = rowColToMask(row, col, this.room.board[0].length);
-        if ((this.markedGoals & mask) !== 0n) {
-            this.markedGoals &= ~mask;
-            this.goalCount--;
-            if (this.room.exploration) {
-                this.exploredGoals = this.getRevealedMask();
-            }
-        }
-    }
-
-    hasMarked(row: number, col: number): boolean {
-        const mask = rowColToMask(row, col, this.room.board[0].length);
-        return (this.markedGoals & mask) !== 0n;
-    }
-
-    hasRevealed(row: number, col: number): boolean {
-        const mask = rowColToMask(row, col, this.room.board[0].length);
-        return (this.exploredGoals & mask) !== 0n;
-    }
-
-    getRevealedMask(): bigint {
-        return (
-            computeRevealedMask(
-                this.markedGoals,
-                this.room.board[0].length,
-                this.room.board.length,
-            ) | this.room.alwaysRevealedMask
-        );
-    }
-
-    obfuscateBoard() {
-        if (this.spectator) {
-            this.exploredGoals = 0n;
-            this.room.players.forEach((player) => {
-                if (!player.spectator) {
-                    this.exploredGoals |= player.getRevealedMask();
-                }
-            });
-        } else {
-            this.exploredGoals = this.getRevealedMask();
-        }
-        return this.room.board.map((row, rowIndex) =>
-            row.map((cell, colIndex) =>
-                this.hasRevealed(rowIndex, colIndex)
-                    ? ({
-                          revealed: true,
-                          goal: cell.goal,
-                          completedPlayers: cell.completedPlayers,
-                      } as RevealedCell)
-                    : ({
-                          revealed: false,
-                          completedPlayers: cell.completedPlayers,
-                      } as HiddenCell),
-            ),
-        );
-    }
-
-    /**
-     * Checks if this player has completed a set of goals on the board
-     *
-     * @param mask The bitmask containing the goals to check for
-     */
-    hasCompletedGoals(mask: bigint) {
-        return (this.markedGoals & mask) === mask;
-    }
-    //#endregion
-
     //#region Races
     async joinRace() {
         return this.room.raceHandler.joinPlayer(this);
diff --git a/api/src/core/Room.ts b/api/src/core/Room.ts
index 0046cb6e..3b56ba6f 100644
--- a/api/src/core/Room.ts
+++ b/api/src/core/Room.ts
@@ -1,4 +1,5 @@
 import { GeneratorSettings } from '@playbingo/shared';
+import { randomUUID } from 'crypto';
 import {
     ChangeColorAction,
     ChangeRaceHandlerAction,
@@ -9,10 +10,13 @@ import {
     MarkAction,
     NewCardAction,
     Player as PlayerData,
+    Team as TeamData,
     RevealedCell,
     ServerMessage,
     UnmarkAction,
     SetChatEnabledAction,
+    JoinTeamAction,
+    SetTeamsEnabledAction,
 } from '@playbingo/types';
 import { BingoMode } from '@prisma/client';
 import { WebSocket } from 'ws';
@@ -31,8 +35,10 @@ import {
     addMarkAction,
     addUnmarkAction,
     createUpdatePlayer,
+    createUpdateTeam,
     setRoomBoard,
     updateRaceHandler,
+    updateTeamsEnabled,
 } from '../database/Rooms';
 import { isStaff } from '../database/Users';
 import {
@@ -62,6 +68,12 @@ import { generateSRLv5 } from './generation/SRLv5';
 import LocalTimer from './integration/races/LocalTimer';
 import RaceHandler from './integration/races/RaceHandler';
 import RacetimeHandler, { RaceData } from './integration/races/RacetimeHandler';
+import Team from './Team';
+
+export type HiddenCell = {
+    revealed: false;
+    completedTeams: string[];
+};
 
 export enum BoardGenerationMode {
     RANDOM = 'Random',
@@ -113,6 +125,7 @@ export default class Room {
     exploration: boolean = false;
     alwaysRevealedMask: bigint = 0n;
     seed: number;
+    teamsEnabled: boolean;
     chatEnabled: boolean = true;
 
     lastGenerationMode: BoardGenerationOptions;
@@ -131,7 +144,9 @@ export default class Room {
     inactivityWarningTimeout?: NodeJS.Timeout;
     closeTimeout?: NodeJS.Timeout;
 
-    players: Map<string, Player>;
+    // players: Map<string, Player>;
+    teams: Map<string, Team>;
+    spectators: Map<string, Player>;
 
     constructor(
         name: string,
@@ -149,6 +164,7 @@ export default class Room {
         explorationStart?: string,
         racetimeUrl?: string,
         generatorSettings?: GeneratorSettings,
+        teamsEnabled: boolean = false,
     ) {
         this.name = name;
         this.game = game;
@@ -190,9 +206,11 @@ export default class Room {
             roomCleanupInactive,
         );
 
-        this.players = new Map<string, Player>();
+        this.teams = new Map<string, Team>();
+        this.spectators = new Map<string, Player>();
 
         this.seed = seed;
+        this.teamsEnabled = teamsEnabled;
 
         if (explorationStart) {
             this.exploration = true;
@@ -237,6 +255,59 @@ export default class Room {
         }
     }
 
+    getAllPlayers(): Player[] {
+        const players = this.teams
+            .values()
+            .flatMap((team) => team.players.values());
+        return [...this.spectators.values(), ...players];
+    }
+
+    getPlayerById(playerId: string): Player | undefined {
+        return this.getAllPlayers().find((player) => player.id === playerId);
+    }
+
+    getPlayerDisplayName(player: Player, team?: Team): string {
+        return this.teamsEnabled && team ? team.name : player.nickname;
+    }
+
+    getTeamDisplayName(team: Team): string {
+        if (this.teamsEnabled) {
+            return team.name;
+        }
+        return team.players.values().next().value?.nickname ?? team.name;
+    }
+
+    deleteTeam(teamId: string) {
+        this.teams.get(teamId)?.destroy();
+        this.teams.delete(teamId);
+    }
+
+    spectatorObfuscateBoard(): (RevealedCell | HiddenCell)[][] {
+        let exploredGoals = 0n;
+        this.teams.forEach((team) => {
+            exploredGoals |= team.getRevealedMask();
+        });
+        return this.board.map((row, rowIndex) =>
+            row.map((cell, colIndex) => {
+                const mask = rowColToMask(
+                    rowIndex,
+                    colIndex,
+                    this.board[0].length,
+                );
+                return (exploredGoals & mask) !== 0n
+                    ? ({
+                          revealed: true,
+                          goal: cell.goal,
+                          completedTeams: cell.completedTeams,
+                      } as RevealedCell)
+                    : ({
+                          revealed: false,
+                          completedTeams: cell.completedTeams,
+                      } as HiddenCell);
+            }),
+        );
+    }
+
     async generateBoard(options: BoardGenerationOptions) {
         this.lastGenerationMode = options;
         const { mode, seed } = options;
@@ -264,7 +335,7 @@ export default class Room {
             this.board = generator.board.map((row) =>
                 row.map((goal) => ({
                     goal: goal,
-                    completedPlayers: [],
+                    completedTeams: [],
                     revealed: true,
                 })),
             );
@@ -366,12 +437,23 @@ export default class Room {
         );
     }
 
-    getPlayers(): PlayerData[] {
-        const players: PlayerData[] = [];
-        this.players.forEach((player) => {
-            players.push(player.toClientData());
-        });
-        return players;
+    getPlayerData(): { teams: TeamData[]; spectators: PlayerData[] } {
+        const teams: TeamData[] = [];
+        this.teams.forEach((team) => teams.push(team.toClientData()));
+        const spectators: PlayerData[] = [];
+        this.spectators.forEach((spectator) =>
+            spectators.push(spectator.toClientData()),
+        );
+        return { teams, spectators };
+    }
+
+    getTeamForPlayer(playerId: string): Team | undefined {
+        for (const team of this.teams.values()) {
+            if (team.players.has(playerId)) {
+                return team;
+            }
+        }
+        return undefined;
     }
 
     //#region Handlers
@@ -380,30 +462,50 @@ export default class Room {
         auth: RoomTokenPayload,
         socket: WebSocket,
     ): ServerMessage {
-        let player: Player | undefined;
+        let player = this.getPlayerById(auth.playerId);
+        let playerTeam = auth.isSpectating
+            ? undefined
+            : player
+              ? this.getTeamForPlayer(player.id)
+              : undefined;
         let newPlayer = false;
-        if (this.players.has(auth.playerId)) {
-            player = this.players.get(auth.playerId);
-            if (!player) {
-                return { action: 'unauthorized' };
+        if (!player && action.payload) {
+            const teamId = auth.isSpectating ? undefined : randomUUID();
+            if (!auth.isSpectating) {
+                playerTeam = new Team(
+                    this,
+                    teamId!,
+                    `Team ${action.payload.nickname}`,
+                    'blue',
+                );
+                player = new Player(
+                    this,
+                    auth.playerId,
+                    action.payload.nickname,
+                    auth.isMonitor,
+                    playerTeam.obfuscateBoard,
+                    teamId,
+                    auth.userId,
+                );
+                playerTeam.addPlayer(player);
+                this.teams.set(playerTeam!.id, playerTeam!);
+            } else {
+                player = new Player(
+                    this,
+                    auth.playerId,
+                    action.payload.nickname,
+                    auth.isMonitor,
+                    this.spectatorObfuscateBoard,
+                    teamId,
+                    auth.userId,
+                );
+                this.spectators.set(auth.playerId, player);
             }
-        } else if (action.payload) {
-            player = new Player(
-                this,
-                auth.playerId,
-                action.payload.nickname,
-                undefined,
-                auth.isSpectating,
-                auth.isMonitor,
-                auth.userId,
-            );
-            this.players.set(player.id, player);
             newPlayer = true;
-        } else {
-            player = this.players.get(auth.playerId);
-            if (!player) {
-                return { action: 'unauthorized' };
-            }
+        }
+
+        if (!player || (!auth.isSpectating && !playerTeam)) {
+            return { action: 'unauthorized' };
         }
 
         if (newPlayer) {
@@ -411,14 +513,17 @@ export default class Room {
                 this.sendChat(`${player.nickname} is now spectating`);
             } else {
                 this.sendChat([
-                    { contents: player.nickname, color: player.color },
-                    ' has joined.',
+                    { contents: player.nickname, color: playerTeam!.color },
+                    ` has joined playing for ${playerTeam!.name}.`,
                 ]);
             }
         }
 
         player.addConnection(auth.uuid, socket);
-        addJoinAction(this.id, player.nickname, player.color).then();
+        addJoinAction(this.id, player.nickname).then();
+        if (playerTeam) {
+            createUpdateTeam(this.id, playerTeam).then();
+        }
         createUpdatePlayer(this.id, player).then();
         return {
             action: 'connected',
@@ -430,7 +535,7 @@ export default class Room {
                     : {
                           hidden: false,
                           board: this.exploration
-                              ? player.obfuscateBoard()
+                              ? player.getBoardView()
                               : this.board,
                       }),
             },
@@ -457,11 +562,60 @@ export default class Room {
                     : { gameActive: this.racetimeEligible, url: undefined },
                 mode: getModeString(this.bingoMode, this.lineCount),
                 variant: this.variantName,
+                teamsEnabled: this.teamsEnabled,
                 startedAt: this.raceHandler?.getStartTime(),
                 finishedAt: this.raceHandler?.getEndTime(),
                 raceHandler: this.raceHandler?.key(),
             },
-            players: this.getPlayers(),
+            players: this.getPlayerData(),
+        };
+    }
+
+    handleJoinTeam(
+        action: JoinTeamAction,
+        auth: RoomTokenPayload,
+    ): ServerMessage {
+        if (!this.teamsEnabled) {
+            return { action: 'forbidden' };
+        }
+        const player = this.getPlayerById(auth.playerId);
+        if (!player) {
+            return { action: 'unauthorized' };
+        }
+        const team = this.teams.get(action.payload.teamId);
+        if (!team) {
+            return { action: 'unauthorized' };
+        }
+        const oldTeam = this.getTeamForPlayer(player.id);
+        if (oldTeam) {
+            oldTeam.removePlayer(player.id);
+            if (oldTeam.players.size === 0) {
+                oldTeam.destroy();
+                this.teams.delete(oldTeam.id);
+            }
+        } else {
+            // player was spectator before
+            this.spectators.delete(player.id);
+        }
+        player.teamId = team.id;
+        team.addPlayer(player);
+        createUpdatePlayer(this.id, player).then();
+        if (oldTeam) {
+            createUpdateTeam(this.id, oldTeam).then();
+        }
+        if (team) {
+            createUpdateTeam(this.id, team).then();
+        }
+        this.sendChat([
+            {
+                contents: player.nickname,
+                color: team.color,
+            },
+            ` joined ${team.name}`,
+        ]);
+        return {
+            action: 'joinedTeam',
+            team: team.toClientData(),
         };
     }
 
@@ -471,7 +625,7 @@ export default class Room {
         token: string,
     ): ServerMessage {
         let player: Player | undefined = undefined;
-        for (const p of this.players.values()) {
+        for (const p of this.getAllPlayers()) {
             if (p.closeConnection(auth.uuid)) {
                 player = p;
                 break;
@@ -482,12 +636,24 @@ export default class Room {
         }
         const hasLeft = !player.hasConnections();
         if (hasLeft) {
-            this.sendChat([
-                { contents: player.nickname, color: player.color },
-                ' has left.',
-            ]);
-            addLeaveAction(this.id, player.nickname, player.color).then();
-            if (this.players.size === 0) {
+            const playerTeam = this.getTeamForPlayer(player.id);
+            if (playerTeam) {
+                playerTeam.removePlayer(player.id);
+                if (playerTeam.players.size === 0) {
+                    playerTeam.destroy();
+                    this.teams.delete(playerTeam.id);
+                }
+            }
+            if (playerTeam) {
+                this.sendChat([
+                    { contents: player.nickname, color: playerTeam.color },
+                    ' has left.',
+                ]);
+            } else {
+                this.sendChat(`${player.nickname} has left.`);
+            }
+            addLeaveAction(this.id, player.nickname).then();
+            if (this.getAllPlayers().length === 0) {
                 this.close();
             }
         }
@@ -499,7 +665,7 @@ export default class Room {
         action: ChatAction,
         auth: RoomTokenPayload,
     ): ServerMessage | undefined {
-        const player = this.players.get(auth.playerId);
+        const player = this.getPlayerById(auth.playerId);
         if (!player) {
             return { action: 'unauthorized' };
         }
@@ -509,7 +675,6 @@ export default class Room {
         addChatAction(
             this.id,
             player.nickname,
-            player.color,
             chatMessage,
         ).then();
     }
@@ -518,29 +683,30 @@ export default class Room {
         action: MarkAction,
         auth: RoomTokenPayload,
     ): ServerMessage | undefined {
-        const player = this.players.get(auth.playerId);
-        if (!player) {
+        const team = this.getTeamForPlayer(auth.playerId);
+        const player = team?.players.get(auth.playerId);
+        if (!team || !player) {
             return { action: 'unauthorized' };
         }
         const { row, col } = action.payload;
         if (row === undefined || col === undefined) return;
-        if (player.hasMarked(row, col)) return;
+        if (team.hasMarked(row, col)) return;
 
         if (
             this.bingoMode === BingoMode.LOCKOUT &&
-            this.board[row][col].completedPlayers.length > 0
+            this.board[row][col].completedTeams.length > 0
         )
             return;
-        this.board[row][col].completedPlayers.push(player.id);
-        this.board[row][col].completedPlayers.sort((a, b) =>
+        this.board[row][col].completedTeams.push(team.id);
+        this.board[row][col].completedTeams.sort((a, b) =>
             a.localeCompare(b),
         );
-        player.mark(row, col);
+        team.mark(row, col);
         this.sendCellUpdate(row, col);
         this.sendChat([
             {
-                contents: player.nickname,
-                color: player.color,
+                contents: this.getPlayerDisplayName(player, team),
+                color: team.color,
             },
             ` marked ${this.board[row][col].goal.goal} (${row},${col})`,
         ]);
@@ -552,20 +718,24 @@ export default class Room {
         action: UnmarkAction,
         auth: RoomTokenPayload,
     ): ServerMessage | undefined {
-        const player = this.players.get(auth.playerId);
-        if (!player) {
+        const team = this.getTeamForPlayer(auth.playerId);
+        const player = team?.players.get(auth.playerId);
+        if (!team || !player) {
             return { action: 'unauthorized' };
         }
         const { row: unRow, col: unCol } = action.payload;
         if (unRow === undefined || unCol === undefined) return;
-        if (!player.hasMarked(unRow, unCol)) return;
-        this.board[unRow][unCol].completedPlayers = this.board[unRow][
+        if (!team.hasMarked(unRow, unCol)) return;
+        this.board[unRow][unCol].completedTeams = this.board[unRow][
             unCol
-        ].completedPlayers.filter((playerId) => playerId !== player.id);
-        player.unmark(unRow, unCol);
+        ].completedTeams.filter((teamId) => teamId !== team.id);
+        team.unmark(unRow, unCol);
         this.sendCellUpdate(unRow, unCol);
         this.sendChat([
-            { contents: player.nickname, color: player.color },
+            {
+                contents: this.getPlayerDisplayName(player, team),
+                color: team.color,
+            },
             ` unmarked ${this.board[unRow][unCol].goal.goal} (${unRow},${unCol})`,
         ]);
         addUnmarkAction(this.id, player.id, unRow, unCol).then();
@@ -576,7 +746,7 @@ export default class Room {
         action: ChangeColorAction,
         auth: RoomTokenPayload,
     ): ServerMessage | undefined {
-        const player = this.players.get(auth.playerId);
+        const player = this.getPlayerById(auth.playerId);
         if (!player) {
             return { action: 'unauthorized' };
         }
@@ -584,17 +754,16 @@ export default class Room {
         if (!color) {
             return;
         }
-        addChangeColorAction(
-            this.id,
-            player.nickname,
-            player.color,
-            color,
-        ).then();
-        player.color = color;
-        createUpdatePlayer(this.id, player).then();
+        const team = this.getTeamForPlayer(player.id);
+        if (!team) {
+            return { action: 'unauthorized' };
+        }
+        addChangeColorAction(this.id, team.name, team.color, color).then();
+        team.color = color;
+        createUpdateTeam(this.id, team).then();
         this.sendChat([
-            { contents: player.nickname, color: player.color },
-            ' has changed their color to ',
+            { contents: this.getTeamDisplayName(team), color: team.color },
+            ' has changed its color to ',
             { contents: color, color },
         ]);
     }
@@ -641,19 +810,22 @@ export default class Room {
 
     handleSocketClose(ws: WebSocket) {
         let player: Player | undefined;
-        for (const p of this.players.values()) {
-            if (p.handleSocketClose(ws)) {
-                player = p;
-            }
-        }
+        this.getAllPlayers().forEach((p) => {
+            if (p.handleSocketClose(ws)) player = p;
+        });
         if (player) {
             if (!player.hasConnections()) {
-                this.sendChat([
-                    { contents: player.nickname, color: player.color },
-                    ' has left.',
-                ]);
-                addLeaveAction(this.id, player.nickname, player.color).then();
-                if (this.players.size === 0) {
+                const team = this.getTeamForPlayer(player.id);
+                if (team) {
+                    this.sendChat([
+                        { contents: player.nickname, color: team.color },
+                        ' has left.',
+                    ]);
+                } else {
+                    this.sendChat(`${player.nickname} has left.`);
+                }
+                addLeaveAction(this.id, player.nickname).then();
+                if (this.getAllPlayers().length === 0) {
                     this.close();
                 }
             }
@@ -677,6 +849,7 @@ export default class Room {
                 newGenerator: this.newGenerator,
                 mode: getModeString(this.bingoMode, this.lineCount),
                 variant: this.variantName,
+                teamsEnabled: this.teamsEnabled,
                 raceHandler: this.raceHandler?.key(),
             },
         });
@@ -701,13 +874,14 @@ export default class Room {
                 newGenerator: this.newGenerator,
                 mode: getModeString(this.bingoMode, this.lineCount),
                 variant: this.variantName,
+                teamsEnabled: this.teamsEnabled,
                 raceHandler: this.raceHandler?.key(),
             },
         });
     }
 
     handleRevealCard(payload: RoomTokenPayload) {
-        const player = this.players.get(payload.playerId);
+        const player = this.getPlayerById(payload.playerId);
         if (!player) {
             return null;
         }
@@ -718,6 +892,12 @@ export default class Room {
         this.chatEnabled = action.payload.enabled;
         this.sendRoomData();
     }
+
+    handleSetTeamsEnabled(action: SetTeamsEnabledAction) {
+        this.teamsEnabled = action.payload.enabled;
+        updateTeamsEnabled(this.id, this.teamsEnabled).then();
+        this.sendRoomData();
+    }
     //#endregion
 
     //#region Send Messages
@@ -768,7 +948,7 @@ export default class Room {
         this.logInfo('Dispatching race data update');
         this.sendServerMessage({
             action: 'syncRaceData',
-            players: this.getPlayers(),
+            players: this.getPlayerData(),
             racetimeConnection: {
                 gameActive: this.racetimeEligible,
                 url: (this.raceHandler as RacetimeHandler).url,
@@ -807,6 +987,7 @@ export default class Room {
                 finishedAt: this.raceHandler?.getEndTime(),
                 raceHandler: this.raceHandler?.key(),
                 chatEnabled: this.chatEnabled,
+                teamsEnabled: this.teamsEnabled,
             },
         });
     }
@@ -815,8 +996,8 @@ export default class Room {
         message: ServerMessage,
         updateInactivity: boolean = true,
     ) {
-        this.players.forEach((player) => {
-            player.sendMessage({ ...message, players: this.getPlayers() });
+        this.getAllPlayers().forEach((player) => {
+            player.sendMessage({ ...message, players: this.getPlayerData() });
         });
 
         if (updateInactivity) {
@@ -828,98 +1009,107 @@ export default class Room {
     }
 
     private checkWinConditions() {
-        this.players.forEach((player) => {
+        this.teams.forEach((team) => {
             if (this.bingoMode === BingoMode.LOCKOUT) {
                 const goalsNeeded = Math.ceil(
                     (this.board.length * this.board[0].length) / 2,
                 );
-                if (!player.goalComplete && player.goalCount >= goalsNeeded) {
+                if (!team.goalComplete && team.goalCount >= goalsNeeded) {
                     this.sendChat([
                         {
-                            contents: player.nickname,
-                            color: player.color,
+                            contents: this.getTeamDisplayName(team),
+                            color: team.color,
                         },
                         ' has achieved lockout!',
                     ]);
-                    player.goalComplete = true;
-                    this.raceHandler?.playerFinished(player);
+                    team.goalComplete = true;
+                    team.players.values().forEach((player) => {
+                        this.raceHandler?.playerFinished(player);
+                    });
                 }
-                if (player.goalComplete && player.goalCount < goalsNeeded) {
+                if (team.goalComplete && team.goalCount < goalsNeeded) {
                     this.sendChat([
                         {
-                            contents: player.nickname,
-                            color: player.color,
+                            contents: this.getTeamDisplayName(team),
+                            color: team.color,
                         },
                         ' no longer has lockout.',
                     ]);
-                    player.goalComplete = false;
-                    this.raceHandler?.playerUnfinshed(player);
+                    team.goalComplete = false;
+                    team.players.values().forEach((player) => {
+                        this.raceHandler?.playerUnfinshed(player);
+                    });
                 }
             } else {
                 if (this.bingoMode === BingoMode.LINES) {
                     const linesComplete = this.victoryMasks.reduce(
                         (count, mask) =>
-                            count + (player.hasCompletedGoals(mask) ? 1 : 0),
+                            count + (team.hasCompletedGoals(mask) ? 1 : 0),
                         0,
                     );
-                    if (linesComplete > player.linesComplete) {
+                    if (linesComplete > team.linesComplete) {
                         this.sendChat([
                             {
-                                contents: player.nickname,
-                                color: player.color,
+                                contents: this.getTeamDisplayName(team),
+                                color: team.color,
                             },
                             ' has completed a line!',
                         ]);
                     }
-                    if (
-                        linesComplete >= this.lineCount &&
-                        !player.goalComplete
-                    ) {
-                        player.goalComplete = true;
-                        this.raceHandler?.playerFinished(player).then();
+                    if (linesComplete >= this.lineCount && !team.goalComplete) {
+                        team.goalComplete = true;
+                        team.players.values().forEach((player) => {
+                            this.raceHandler?.playerFinished(player).then();
+                        });
                         this.sendChat([
                             {
-                                contents: player.nickname,
-                                color: player.color,
+                                contents: this.getTeamDisplayName(team),
+                                color: team.color,
                             },
                             ' has completed the goal!',
                         ]);
                     } else if (
                         linesComplete < this.lineCount &&
-                        player.goalComplete
+                        team.goalComplete
                     ) {
-                        player.goalComplete = false;
-                        this.raceHandler?.playerUnfinshed(player);
+                        team.goalComplete = false;
+                        team.players.values().forEach((player) => {
+                            this.raceHandler?.playerUnfinshed(player).then();
+                        });
                         this.sendChat([
                             {
-                                contents: player.nickname,
-                                color: player.color,
+                                contents: this.getTeamDisplayName(team),
+                                color: team.color,
                             },
                             ' has no longer completed the goal.',
                         ]);
                     }
-                    player.linesComplete = linesComplete;
+                    team.linesComplete = linesComplete;
                 } else {
                     const complete = this.victoryMasks.every((mask) =>
-                        player.hasCompletedGoals(mask),
+                        team.hasCompletedGoals(mask),
                     );
-                    if (complete && !player.goalComplete) {
-                        player.goalComplete = true;
-                        this.raceHandler?.playerFinished(player);
+                    if (complete && !team.goalComplete) {
+                        team.goalComplete = true;
+                        team.players.values().forEach((player) => {
+                            this.raceHandler?.playerFinished(player);
+                        });
                         this.sendChat([
                             {
-                                contents: player.nickname,
-                                color: player.color,
+                                contents: this.getTeamDisplayName(team),
+                                color: team.color,
                             },
                             ' has achieved blackout!',
                         ]);
-                    } else if (!complete && player.goalComplete) {
-                        player.goalComplete = false;
-                        this.raceHandler?.playerUnfinshed(player);
+                    } else if (!complete && team.goalComplete) {
+                        team.goalComplete = false;
+                        team.players.values().forEach((player) => {
+                            this.raceHandler?.playerUnfinshed(player);
+                        });
                         this.sendChat([
                             {
-                                contents: player.nickname,
-                                color: player.color,
+                                contents: this.getTeamDisplayName(team),
+                                color: team.color,
                             },
                             ' no longer has blackout.',
                         ]);
@@ -928,8 +1118,8 @@ export default class Room {
             }
         });
         let allComplete = true;
-        this.players.forEach((player) => {
-            if (!player.spectator && !player.goalComplete) {
+        this.teams.forEach((team) => {
+            if (!team.goalComplete) {
                 allComplete = false;
             }
         });
@@ -968,13 +1158,13 @@ export default class Room {
             return false;
         }
 
-        const player = this.players.get(
+        const player = this.getPlayerById(
             `${isSession ? 'session' : 'user'}:${user}`,
         );
         if (player) {
             return {
                 isMonitor: player.monitor,
-                isSpectating: player.spectator,
+                isSpectating: this.spectators.has(player.id),
             };
         }
 
@@ -1001,7 +1191,7 @@ export default class Room {
     }
 
     joinRaceRoom(racetimeId: string, authToken: RoomTokenPayload) {
-        const player = this.players.get(authToken.playerId);
+        const player = this.getPlayerById(authToken.playerId);
         if (!player) {
             this.logWarn('Unable to find a player for a verified room token');
             return false;
@@ -1011,7 +1201,7 @@ export default class Room {
     }
 
     leaveRaceRoom(authToken: RoomTokenPayload) {
-        const player = this.players.get(authToken.playerId);
+        const player = this.getPlayerById(authToken.playerId);
         if (!player) {
             this.logWarn('Unable to find a player for a verified room token');
             return false;
@@ -1025,7 +1215,7 @@ export default class Room {
     }
 
     readyPlayer(roomAuth: RoomTokenPayload) {
-        const player = this.players.get(roomAuth.playerId);
+        const player = this.getPlayerById(roomAuth.playerId);
         if (!player) {
             this.logWarn('Unable to find a player for a verified room token');
             return false;
@@ -1035,7 +1225,7 @@ export default class Room {
     }
 
     unreadyPlayer(roomAuth: RoomTokenPayload) {
-        const player = this.players.get(roomAuth.playerId);
+        const player = this.getPlayerById(roomAuth.playerId);
         if (!player) {
             this.logWarn(
                 'Unable to find an identity for a verified room token',
@@ -1081,7 +1271,7 @@ export default class Room {
      */
     canClose() {
         if (Date.now() - this.lastMessage > roomCleanupInactive) {
-            return this.players.size <= 0;
+            return this.getAllPlayers().length <= 0;
         }
         return false;
     }
@@ -1092,7 +1282,7 @@ export default class Room {
     close() {
         this.logInfo('Closing room.');
         this.sendSystemMessage('This room has been closed due to inactivity.');
-        this.players.forEach((player) => {
+        this.getAllPlayers().forEach((player) => {
             player.connections.forEach((connection) => {
                 this.handleSocketClose(connection);
                 connection.close(1001, 'Room is closing.');
@@ -1102,13 +1292,15 @@ export default class Room {
     }
 
     revealCardForPlayer(player: Player) {
-        this.sendChat([
-            {
-                contents: player.nickname,
-                color: player.color,
-            },
-            ' has revealed the card.',
-        ]);
+        const team = this.getTeamForPlayer(player.id);
+        if (team) {
+            this.sendChat([
+                { contents: player.nickname, color: team.color },
+                ' has revealed the card.',
+            ]);
+        } else {
+            this.sendChat(`${player.nickname} has revealed the card.`);
+        }
         player.sendMessage({
             action: 'syncBoard',
             board: {
@@ -1121,7 +1313,7 @@ export default class Room {
     }
 
     revealCardForAllPlayers() {
-        this.players.forEach((player) => {
+        this.getAllPlayers().forEach((player) => {
             this.revealCardForPlayer(player);
         });
     }
diff --git a/api/src/core/RoomServer.ts b/api/src/core/RoomServer.ts
index 627eb347..a7d2767d 100644
--- a/api/src/core/RoomServer.ts
+++ b/api/src/core/RoomServer.ts
@@ -8,6 +8,8 @@ import {
 import { roomCleanupInterval } from '../Environment';
 import { logInfo, logWarn } from '../Logger';
 import Room from './Room';
+import Team from './Team';
+import Player from './Player';
 
 export const roomWebSocketServer: WebSocketServer = new WebSocketServer({
     noServer: true,
@@ -104,6 +106,12 @@ roomWebSocketServer.on('connection', (ws, req) => {
                     ws.send(JSON.stringify(unmarkResult));
                 }
                 break;
+            case 'joinTeam':
+                const joinTeamResult = room.handleJoinTeam(action, payload);
+                if (joinTeamResult) {
+                    ws.send(JSON.stringify(joinTeamResult));
+                }
+                break;
             case 'chat':
                 const chatResult = room.handleChat(action, payload);
                 if (chatResult) {
@@ -135,18 +143,30 @@ roomWebSocketServer.on('connection', (ws, req) => {
                     payload.playerId.split(':')[1],
                     payload.userId,
                 );
-                const player = room.players.get(payload.playerId);
+                const player = room.getPlayerById(payload.playerId);
+                const team = player
+                    ? room.getTeamForPlayer(player.id)
+                    : undefined;
                 if (player) {
-                    player.spectator = action.payload.spectate;
-                    player.sendMessage({
-                        action: 'reauthenticate',
-                        authToken: newToken,
-                    });
-                    if (player.spectator) {
-                        player.markedGoals = 0n;
-                        player.goalCount = 0;
+                    if (action.payload.spectate) {
+                        if (team) {
+                            team.removePlayer(player.id);
+                            if (team.players.size === 0) {
+                                team.destroy();
+                                room.teams.delete(team.id);
+                            }
+                        }
+                        player.sendMessage({
+                            action: 'reauthenticate',
+                            authToken: newToken,
+                        });
                         room.sendChat(`${player.nickname} is now spectating`);
+                        break;
                     } else {
+                        player.sendMessage({
+                            action: 'reauthenticate',
+                            authToken: newToken,
+                        });
                         room.sendChat(`${player.nickname} is now playing`);
                     }
                 }
@@ -163,6 +183,9 @@ roomWebSocketServer.on('connection', (ws, req) => {
             case 'setChatEnabled':
                 room.handleSetChatEnabled(action);
                 break;
+            case 'setTeamsEnabled':
+                room.handleSetTeamsEnabled(action);
+                break;
         }
     });
     ws.on('close', (code, reason) => {
diff --git a/api/src/core/Team.ts b/api/src/core/Team.ts
new file mode 100644
index 00000000..ba7e1f54
--- /dev/null
+++ b/api/src/core/Team.ts
@@ -0,0 +1,139 @@
+import Room from './Room';
+import Player from './Player';
+import { HiddenCell, RevealedCell, Team as TeamData } from '@playbingo/types';
+import { computeRevealedMask, rowColToMask } from '../util/RoomUtils';
+
+export default class Team {
+    room: Room;
+    /**
+     * Unique id for the team
+     */
+    id: string;
+    /**
+     * The name of the team
+     */
+    name: string;
+    /** The color used to display this team's marks */
+    color: string;
+    /**
+     * The players on the team
+     */
+    players: Map<string, Player>;
+
+    /** Bitset of the goals the player has marked */
+    markedGoals: bigint;
+    /** The number of goals the player has marked */
+    goalCount: number;
+    /** Whether or not the player has completed the goal of the room */
+    goalComplete: boolean;
+    linesComplete: number;
+    /** Bitset of goals that are revealed for the player in exploration based
+     * modes */
+    exploredGoals: bigint;
+
+    constructor(room: Room, id: string, name: string, color: string = 'blue') {
+        this.room = room;
+        ((this.id = id), (this.name = name), (this.color = color));
+        this.players = new Map<string, Player>();
+        this.markedGoals = 0n;
+        this.goalCount = 0;
+        this.goalComplete = false;
+        this.linesComplete = 0;
+        this.exploredGoals = 0n;
+    }
+
+    addPlayer(player: Player) {
+        this.players.set(player.id, player);
+    }
+
+    removePlayer(id: string) {
+        this.players.delete(id);
+    }
+
+    destroy() {
+        this.players.clear();
+    }
+
+    toClientData(): TeamData {
+        return {
+            id: this.id,
+            name: this.name,
+            color: this.color,
+            players: Array.from(this.players.values()).map((player) =>
+                player.toClientData(),
+            ),
+            goalCount: this.goalCount
+        };
+    }
+
+    //#region Goal Tracking
+    mark(row: number, col: number) {
+        const mask = rowColToMask(row, col, this.room.board[0].length);
+        if ((this.markedGoals & mask) === 0n) {
+            this.markedGoals |= mask;
+            this.goalCount++;
+            if (this.room.exploration) {
+                this.exploredGoals = this.getRevealedMask();
+            }
+        }
+    }
+
+    unmark(row: number, col: number) {
+        const mask = rowColToMask(row, col, this.room.board[0].length);
+        if ((this.markedGoals & mask) !== 0n) {
+            this.markedGoals &= ~mask;
+            this.goalCount--;
+            if (this.room.exploration) {
+                this.exploredGoals = this.getRevealedMask();
+            }
+        }
+    }
+
+    hasMarked(row: number, col: number): boolean {
+        const mask = rowColToMask(row, col, this.room.board[0].length);
+        return (this.markedGoals & mask) !== 0n;
+    }
+
+    hasRevealed(row: number, col: number): boolean {
+        const mask = rowColToMask(row, col, this.room.board[0].length);
+        return (this.exploredGoals & mask) !== 0n;
+    }
+
+    getRevealedMask(): bigint {
+        return (
+            computeRevealedMask(
+                this.markedGoals,
+                this.room.board[0].length,
+                this.room.board.length,
+            ) | this.room.alwaysRevealedMask
+        );
+    }
+
+    obfuscateBoard() {
+        this.exploredGoals = this.getRevealedMask();
+        return this.room.board.map((row, rowIndex) =>
+            row.map((cell, colIndex) =>
+                this.hasRevealed(rowIndex, colIndex)
+                    ? ({
+                          revealed: true,
+                          goal: cell.goal,
+                          completedTeams: cell.completedTeams,
+                      } as RevealedCell)
+                    : ({
+                          revealed: false,
+                          completedTeams: cell.completedTeams,
+                      } as HiddenCell),
+            ),
+        );
+    }
+
+    /**
+     * Checks if this player has completed a set of goals on the board
+     *
+     * @param mask The bitmask containing the goals to check for
+     */
+    hasCompletedGoals(mask: bigint) {
+        return (this.markedGoals & mask) === mask;
+    }
+    //#endregion
+}
diff --git a/api/src/core/integration/races/LocalTimer.ts b/api/src/core/integration/races/LocalTimer.ts
index e5061d20..5077a253 100644
--- a/api/src/core/integration/races/LocalTimer.ts
+++ b/api/src/core/integration/races/LocalTimer.ts
@@ -66,7 +66,7 @@ export default class LocalTimer implements RaceHandler {
         this.finishedAt = undefined;
         updateStartTime(this.room.id, null).then();
         updateFinishTime(this.room.id, null).then();
-        this.room.players.forEach((player) => {
+        this.room.getAllPlayers().forEach((player) => {
             player.finishedAt = undefined;
             createUpdatePlayer(this.room.id, player).then();
         });
diff --git a/api/src/database/Rooms.ts b/api/src/database/Rooms.ts
index e4906519..c5e28816 100644
--- a/api/src/database/Rooms.ts
+++ b/api/src/database/Rooms.ts
@@ -2,6 +2,7 @@ import { BingoMode, RaceHandler, RoomActionType } from '@prisma/client';
 import { prisma } from './Database';
 import { JsonObject } from '@prisma/client/runtime/library';
 import Player from '../core/Player';
+import Team from '../core/Team';
 
 export const createRoom = (
     slug: string,
@@ -15,6 +16,7 @@ export const createRoom = (
     variant?: string,
     explorationStart?: string,
     seed?: number,
+    teamsEnabled: boolean = false,
 ) => {
     return prisma.room.create({
         data: {
@@ -30,6 +32,7 @@ export const createRoom = (
             exploration: !!explorationStart,
             explorationStart,
             seed,
+            teamsEnabled,
         },
     });
 };
@@ -48,11 +51,11 @@ const addRoomAction = (
     });
 };
 
-export const addJoinAction = (room: string, nickname: string, color: string) =>
-    addRoomAction(room, RoomActionType.JOIN, { nickname, color });
+export const addJoinAction = (room: string, nickname: string) =>
+    addRoomAction(room, RoomActionType.JOIN, { nickname });
 
-export const addLeaveAction = (room: string, nickname: string, color: string) =>
-    addRoomAction(room, RoomActionType.LEAVE, { nickname, color });
+export const addLeaveAction = (room: string, nickname: string) =>
+    addRoomAction(room, RoomActionType.LEAVE, { nickname });
 
 export const addMarkAction = (
     room: string,
@@ -71,18 +74,17 @@ export const addUnmarkAction = (
 export const addChatAction = (
     room: string,
     nickname: string,
-    color: string,
     message: string,
-) => addRoomAction(room, RoomActionType.CHAT, { nickname, color, message });
+) => addRoomAction(room, RoomActionType.CHAT, { nickname, message });
 
 export const addChangeColorAction = (
     room: string,
-    nickname: string,
+    teamName: string,
     oldColor: string,
     newColor: string,
 ) =>
     addRoomAction(room, RoomActionType.CHANGECOLOR, {
-        nickname,
+        teamName,
         oldColor,
         newColor,
     });
@@ -102,7 +104,7 @@ export const getAllRooms = () => {
 export const getRoomFromSlug = (slug: string) => {
     return prisma.room.findUnique({
         where: { slug },
-        include: { history: true, game: true, players: true },
+        include: { history: true, game: true, players: true, teams: true },
     });
 };
 
@@ -123,28 +125,48 @@ export const createUpdatePlayer = async (room: string, player: Player) => {
         create: {
             key: player.id,
             nickname: player.nickname,
-            color: player.color,
             room: { connect: { id: room } },
             user: player.userId
                 ? { connect: { id: player.userId } }
                 : undefined,
-            spectator: player.spectator,
+            team: player.teamId
+                ? { connect: { id: player.teamId } }
+                : undefined,
+            spectator: !player.teamId,
             monitor: player.monitor,
             finishedAt: player.finishedAt,
         },
         update: {
             nickname: player.nickname,
-            color: player.color,
             user: player.userId
                 ? { connect: { id: player.userId } }
                 : { disconnect: true },
-            spectator: player.spectator,
             monitor: player.monitor,
+            team: player.teamId
+                ? { connect: { id: player.teamId } }
+                : { disconnect: true },
+            spectator: !player.teamId,
             finishedAt: player.finishedAt ?? null,
         },
     });
 };
 
+export const createUpdateTeam = async (room: string, team: Team) => {
+    return prisma.team.upsert({
+        where: { id_roomId: { id: team.id, roomId: room } },
+        create: {
+            key: team.id,
+            name: team.name,
+            color: team.color,
+            room: { connect: { id: room } },
+        },
+        update: {
+            name: team.name,
+            color: team.color,
+        },
+    });
+};
+
 export const updateStartTime = async (room: string, startedAt: Date | null) => {
     return prisma.room.update({
         where: { id: room },
@@ -170,3 +192,6 @@ export const updateRaceHandler = async (
         data: { raceHandler },
     });
 };
+
+export const updateTeamsEnabled = async (room: string, teamsEnabled: boolean) =>
+    prisma.room.update({ where: { id: room }, data: { teamsEnabled } });
diff --git a/api/src/routes/rooms/Rooms.ts b/api/src/routes/rooms/Rooms.ts
index 60b189bc..d452b200 100644
--- a/api/src/routes/rooms/Rooms.ts
+++ b/api/src/routes/rooms/Rooms.ts
@@ -32,6 +32,7 @@ import { GenerationFailedError } from '../../core/generation/GenerationFailedErr
 import RacetimeHandler from '../../core/integration/races/RacetimeHandler';
 import LocalTimer from '../../core/integration/races/LocalTimer';
 import { error } from 'console';
+import Team from "../../core/Team";
 
 const MIN_ROOM_GOALS_REQUIRED = 25;
 const rooms = Router();
@@ -82,6 +83,7 @@ rooms.post('/', async (req, res) => {
         exploration,
         explorationStart,
         explorationStartCount,
+        teamsEnabled,
     } = req.body;
     const seed = req.body.seed ?? Math.ceil(999999 * Math.random());
 
@@ -191,6 +193,7 @@ rooms.post('/', async (req, res) => {
                 : explorationStart
             : undefined,
         seed,
+        !!teamsEnabled,
     );
     const room = new Room(
         name,
@@ -214,6 +217,7 @@ rooms.post('/', async (req, res) => {
             : undefined,
         '',
         generatorSettings,
+        !!teamsEnabled,
     );
     const options: BoardGenerationOptions = {
         mode: BoardGenerationMode.RANDOM,
@@ -270,7 +274,7 @@ rooms.post('/', async (req, res) => {
 });
 
 async function getOrLoadRoom(slug: string): Promise<Room | null> {
-    let room = allRooms.get(slug);
+    const room = allRooms.get(slug);
     if (room) return room;
 
     const dbRoom = await getRoomFromSlug(slug);
@@ -324,13 +328,14 @@ async function getOrLoadRoom(slug: string): Promise<Room | null> {
         dbRoom.explorationStart ?? undefined,
         dbRoom.racetimeRoom ?? '',
         generatorSettings,
+        dbRoom.teamsEnabled,
     );
 
     if (generatorSettings?.boardLayout.mode === 'custom') {
         newRoom.board = chunk(
             (await getGoalList(dbRoom.board)).map((goal) => ({
                 goal: goal,
-                completedPlayers: [],
+                completedTeams: [],
                 revealed: true,
             })),
             generatorSettings.boardLayout.layout[0].length,
@@ -339,7 +344,7 @@ async function getOrLoadRoom(slug: string): Promise<Room | null> {
         newRoom.board = chunk(
             (await getGoalList(dbRoom.board)).map((goal) => ({
                 goal: goal,
-                completedPlayers: [],
+                completedTeams: [],
                 revealed: true,
             })),
             5,
@@ -347,18 +352,48 @@ async function getOrLoadRoom(slug: string): Promise<Room | null> {
     }
     newRoom.computeVictoryMasks();
 
+    dbRoom.teams.forEach((dbTeam) => {
+        const team = new Team(
+            newRoom,
+            dbTeam.key,
+            dbTeam.name,
+            dbTeam.color,
+        );
+        newRoom.teams.set(team.id, team);
+    })
+
     dbRoom.players.forEach((dbPlayer) => {
+        // Player is spectator, no need to add a team
+        if (!dbPlayer.teamId) {
+            const player = new Player(
+                newRoom,
+                dbPlayer.key,
+                dbPlayer.nickname,
+                dbPlayer.monitor,
+                newRoom.spectatorObfuscateBoard,
+                undefined,
+                dbPlayer.userId ?? undefined,
+            );
+            player.finishedAt = dbPlayer.finishedAt?.toISOString();
+            newRoom.spectators.set(player.id, player);
+            return;
+        }
+        // player is not spectator and is on a team
+        const team = newRoom.teams.get(dbPlayer.teamId);
+        if (!team) {
+            // This really shouldn't happen, this is mostly here for type safety
+            throw new Error(`Team for player ${dbPlayer.nickname} not found, please report this to a developer.`);
+        }
         const player = new Player(
             newRoom,
             dbPlayer.key,
             dbPlayer.nickname,
-            dbPlayer.color,
-            dbPlayer.spectator,
             dbPlayer.monitor,
+            team.obfuscateBoard,
+            team.id,
             dbPlayer.userId ?? undefined,
-        );
-        player.finishedAt = dbPlayer.finishedAt?.toISOString();
-        newRoom.players.set(player.id, player);
+        )
+        team.players.set(player.id, player);
     });
 
     dbRoom.history.forEach((action) => {
@@ -373,7 +408,11 @@ async function getOrLoadRoom(slug: string): Promise<Room | null> {
             player: playerId,
         } = action.payload as any;
 
-        const player = newRoom.players.get(playerId)!;
+        const player = newRoom.getPlayerById(playerId)!;
+        let team: Team | undefined;
+        if (player.teamId) {
+            team = newRoom.teams.get(player.teamId)
+        }
 
         switch (action.action) {
             case 'JOIN':
@@ -386,28 +425,34 @@ async function getOrLoadRoom(slug: string): Promise<Room | null> {
                 newRoom.sendChat([{ contents: nickname, color }, ' has left.']);
                 break;
             case 'MARK':
-                if (!player.hasMarked(row, col)) {
-                    newRoom.board[row][col].completedPlayers.push(playerId);
-                    newRoom.board[row][col].completedPlayers.sort((a, b) =>
+                if (!team) {
+                    break;
+                }
+                if (!team.hasMarked(row, col)) {
+                    newRoom.board[row][col].completedTeams.push(team.id);
+                    newRoom.board[row][col].completedTeams.sort((a, b) =>
                         a.localeCompare(b),
                     );
-                    player.mark(row, col);
+                    team.mark(row, col);
                     newRoom.sendCellUpdate(row, col);
                     newRoom.sendChat([
-                        { contents: player.nickname, color: player.color },
+                        { contents: team.name, color: team.color },
                         ` marked ${newRoom.board[row][col].goal.goal} (${row},${col})`,
                     ]);
                 }
                 break;
             case 'UNMARK':
-                if (player.hasMarked(row, col)) {
-                    newRoom.board[row][col].completedPlayers = newRoom.board[
+                if (!team) {
+                    break;
+                }
+                if (team.hasMarked(row, col)) {
+                    newRoom.board[row][col].completedTeams = newRoom.board[
                         row
-                    ][col].completedPlayers.filter((p) => p !== playerId);
-                    player.unmark(row, col);
+                    ][col].completedTeams.filter((teamId) => teamId !== team.id);
+                    team.unmark(row, col);
                     newRoom.sendCellUpdate(row, col);
                     newRoom.sendChat([
-                        { contents: player.nickname, color: player.color },
+                        { contents: team.name, color: team.color },
                         ` unmarked ${newRoom.board[row][col].goal.goal} (${row},${col})`,
                     ]);
                 }
@@ -416,6 +461,9 @@ async function getOrLoadRoom(slug: string): Promise<Room | null> {
                 newRoom.sendChat(`${nickname}: ${message}`);
                 break;
             case 'CHANGECOLOR':
+                if (team) {
+                    team.color = newColor;
+                }
                 newRoom.sendChat([
                     { contents: nickname, color: oldColor },
                     ' has changed their color to ',
@@ -470,6 +518,7 @@ rooms.get('/:slug', async (req, res) => {
         mode: room.bingoMode,
         variant: room.variantName,
         chatEnabled: room.chatEnabled,
+        teamsEnabled: room.teamsEnabled,
     };
 
     const userKey = req.session.user ?? req.session.id;
diff --git a/api/src/tests/core/Player.test.ts b/api/src/tests/core/Player.test.ts
deleted file mode 100644
index 41da1a5a..00000000
--- a/api/src/tests/core/Player.test.ts
+++ /dev/null
@@ -1,135 +0,0 @@
-import { mock } from 'jest-mock-extended';
-import Player from '../../core/Player';
-import Room from '../../core/Room';
-import { RevealedCell } from '@playbingo/types';
-
-const room = mock<Room>();
-room.board = [Array(5).fill(mock<RevealedCell>()), [], [], [], []];
-
-const createPlayer = () =>
-    new Player(room, 'test', 'Test Player', 'blue', false, false);
-
-describe('Goal Tracking', () => {
-    beforeEach(() => {
-        room.exploration = false;
-    });
-
-    it('Correctly marks unmarked cells', () => {
-        const player = createPlayer();
-        player.mark(0, 0);
-        expect(player.markedGoals).toEqual(1n);
-        expect(player.goalCount).toEqual(1);
-        player.mark(0, 4);
-        expect(player.markedGoals).toEqual(BigInt(0b10001));
-        expect(player.goalCount).toEqual(2);
-        player.mark(0, 3);
-        player.mark(1, 4);
-        expect(player.markedGoals).toEqual(BigInt(0b1000011001));
-        expect(player.goalCount).toEqual(4);
-    });
-
-    it("Doesn't change marked cells when marking a cell that is already marked", () => {
-        const player = createPlayer();
-        player.mark(0, 0);
-        player.mark(1, 2);
-        const original = player.markedGoals;
-        player.mark(1, 2);
-        expect(player.markedGoals).toEqual(original);
-        expect(player.goalCount).toEqual(2);
-    });
-
-    it('Correctly unmarks marked cells', () => {
-        const player = createPlayer();
-        player.mark(0, 0);
-        player.mark(1, 2);
-        player.mark(1, 4);
-        player.mark(2, 2);
-        player.mark(3, 0);
-        player.mark(3, 2);
-        player.unmark(2, 2);
-        expect(player.markedGoals).toEqual(BigInt(0b101000001010000001));
-        expect(player.goalCount).toEqual(5);
-        player.unmark(3, 2);
-        player.unmark(1, 4);
-        expect(player.goalCount).toEqual(3);
-        expect(player.markedGoals).toEqual(BigInt(0b1000000010000001));
-    });
-
-    it("Doesn't change marked cells when unmarking a cell that is not marked", () => {
-        const player = createPlayer();
-        player.mark(0, 0);
-        player.mark(1, 3);
-        const original = player.markedGoals;
-        player.unmark(3, 0);
-        expect(player.markedGoals).toEqual(original);
-        expect(player.goalCount).toEqual(2);
-    });
-
-    it('Correctly tells if a cell is marked', () => {
-        const player = createPlayer();
-        const toMark = [3, 7, 9, 16, 21];
-        const unmarked = Array.from(Array(25), (_, index) => index).filter(
-            (index) => !toMark.includes(index),
-        );
-        toMark.forEach((index) =>
-            player.mark(index % 5, Math.floor(index / 5)),
-        );
-        toMark.forEach((index) =>
-            expect(
-                player.hasMarked(index % 5, Math.floor(index / 5)),
-            ).toBeTruthy(),
-        );
-        unmarked.forEach((index) =>
-            expect(
-                player.hasMarked(index % 5, Math.floor(index / 5)),
-            ).toBeFalsy(),
-        );
-    });
-
-    it('Correctly determines if a set of goals is marked', () => {
-        const player = createPlayer();
-        player.mark(0, 0);
-        player.mark(0, 1);
-        player.mark(0, 2);
-        player.mark(0, 3);
-        player.mark(0, 4);
-        player.mark(1, 0);
-        player.mark(2, 0);
-        player.mark(3, 0);
-        player.mark(4, 0);
-        const row1Mask = BigInt(0b11111);
-        const row2Mask = BigInt(0b1111100000);
-        const col1Mask = BigInt(0b0000100001000010000100001);
-        expect(player.hasCompletedGoals(row1Mask)).toBeTruthy();
-        expect(player.hasCompletedGoals(col1Mask)).toBeTruthy();
-        expect(player.hasCompletedGoals(row2Mask)).toBeFalsy();
-    });
-});
-
-describe('Exploration', () => {
-    beforeEach(() => {
-        room.exploration = true;
-        room.alwaysRevealedMask = 1n;
-    });
-
-    it('Correctly reveals cells when marking with exploration enabled', () => {
-        const player = createPlayer();
-        player.room.exploration = true;
-        player.mark(2, 2);
-        expect(player.hasRevealed(1, 2)).toBeTruthy();
-        expect(player.hasRevealed(3, 2)).toBeTruthy();
-        expect(player.hasRevealed(2, 1)).toBeTruthy();
-        expect(player.hasRevealed(2, 3)).toBeTruthy();
-    });
-
-    it('Correctly hides cells when marking with exploration enabled', () => {
-        const player = createPlayer();
-        player.room.exploration = true;
-        player.mark(2, 2);
-        player.unmark(2, 2);
-        expect(player.hasRevealed(1, 2)).toBeFalsy();
-        expect(player.hasRevealed(3, 2)).toBeFalsy();
-        expect(player.hasRevealed(2, 1)).toBeFalsy();
-        expect(player.hasRevealed(2, 3)).toBeFalsy();
-    });
-});
diff --git a/api/src/tests/core/RoomTeams.test.ts b/api/src/tests/core/RoomTeams.test.ts
new file mode 100644
index 00000000..1413c7fe
--- /dev/null
+++ b/api/src/tests/core/RoomTeams.test.ts
@@ -0,0 +1,177 @@
+import { BingoMode } from '@prisma/client';
+import {
+    ChangeColorAction,
+    JoinAction,
+    JoinTeamAction,
+    MarkAction,
+    RevealedCell,
+    SetTeamsEnabledAction,
+    UnmarkAction,
+} from '@playbingo/types';
+import { WebSocket } from 'ws';
+import { RoomTokenPayload } from '../../auth/RoomAuth';
+import Room from '../../core/Room';
+import {
+    createUpdatePlayer,
+    createUpdateTeam,
+    updateTeamsEnabled,
+} from '../../database/Rooms';
+
+jest.mock('../../database/Rooms', () => ({
+    addChangeColorAction: jest.fn().mockResolvedValue(undefined),
+    addChatAction: jest.fn().mockResolvedValue(undefined),
+    addJoinAction: jest.fn().mockResolvedValue(undefined),
+    addLeaveAction: jest.fn().mockResolvedValue(undefined),
+    addMarkAction: jest.fn().mockResolvedValue(undefined),
+    addUnmarkAction: jest.fn().mockResolvedValue(undefined),
+    createUpdatePlayer: jest.fn().mockResolvedValue(undefined),
+    createUpdateTeam: jest.fn().mockResolvedValue(undefined),
+    setRoomBoard: jest.fn().mockResolvedValue(undefined),
+    updateRaceHandler: jest.fn().mockResolvedValue(undefined),
+    updateTeamsEnabled: jest.fn().mockResolvedValue(undefined),
+}));
+
+const createRoom = () => {
+    const room = new Room(
+        'Room',
+        'Game',
+        'game',
+        'room',
+        '',
+        'room-id',
+        false,
+        BingoMode.LINES,
+        1,
+        false,
+        'Normal',
+        1,
+    );
+    room.board = Array.from({ length: 5 }, (_, row) =>
+        Array.from(
+            { length: 5 },
+            (_, col) =>
+                ({
+                    goal: {
+                        id: `${row}-${col}`,
+                        goal: 'Goal',
+                        description: null,
+                    },
+                    completedTeams: [],
+                    revealed: true,
+                }) as RevealedCell,
+        ),
+    );
+    room.computeVictoryMasks();
+    return room;
+};
+
+const auth = (playerId: string, isSpectating = false): RoomTokenPayload => ({
+    roomSlug: 'room',
+    uuid: `${playerId}-connection`,
+    playerId,
+    isSpectating,
+    isMonitor: true,
+});
+
+const socket = () => ({ readyState: 0, send: jest.fn() }) as unknown as WebSocket;
+
+const joinAction = (nickname: string) =>
+    ({ action: 'join', payload: { nickname } }) as JoinAction;
+
+describe('Room team workflows', () => {
+    afterEach(() => {
+        jest.clearAllMocks();
+    });
+
+    it('creates a team for a joining player and exposes team-owned state', () => {
+        const room = createRoom();
+        const result = room.handleJoin(joinAction('Alice'), auth('alice'), socket());
+
+        expect(result.action).toBe('connected');
+        expect(room.teams.size).toBe(1);
+        expect(result).toMatchObject({
+            roomData: { teamsEnabled: false },
+        });
+        const team = room.getTeamForPlayer('alice');
+        expect(team).toMatchObject({ name: 'Team Alice', color: 'blue' });
+        expect(room.getPlayerById('alice')?.teamId).toBe(team?.id);
+        expect(createUpdateTeam).toHaveBeenCalledWith('room-id', team);
+        expect(createUpdatePlayer).toHaveBeenCalledWith(
+            'room-id',
+            room.getPlayerById('alice'),
+        );
+        expect(room.chatHistory).toContainEqual([
+            { contents: 'Alice', color: 'blue' },
+            ' has joined.',
+        ]);
+    });
+
+    it('tracks marks by team ID and applies the team color', () => {
+        const room = createRoom();
+        room.handleJoin(joinAction('Alice'), auth('alice'), socket());
+        const team = room.getTeamForPlayer('alice')!;
+
+        room.handleMark(
+            { action: 'mark', payload: { row: 0, col: 0 } } as MarkAction,
+            auth('alice'),
+        );
+        expect(room.board[0][0].completedTeams).toEqual([team.id]);
+        expect(team.hasMarked(0, 0)).toBe(true);
+
+        room.handleUnmark(
+            { action: 'unmark', payload: { row: 0, col: 0 } } as UnmarkAction,
+            auth('alice'),
+        );
+        expect(room.board[0][0].completedTeams).toEqual([]);
+        expect(team.hasMarked(0, 0)).toBe(false);
+
+        room.handleChangeColor(
+            { action: 'changeColor', payload: { color: 'red' } } as ChangeColorAction,
+            auth('alice'),
+        );
+        expect(team.color).toBe('red');
+        expect(createUpdateTeam).toHaveBeenLastCalledWith('room-id', team);
+    });
+
+    it('permits joining another team only when teams are enabled', () => {
+        const room = createRoom();
+        room.handleJoin(joinAction('Alice'), auth('alice'), socket());
+        room.handleJoin(joinAction('Bob'), auth('bob'), socket());
+        const aliceTeam = room.getTeamForPlayer('alice')!;
+
+        const joinTeam = {
+            action: 'joinTeam',
+            payload: { teamId: aliceTeam.id },
+        } as JoinTeamAction;
+        expect(room.handleJoinTeam(joinTeam, auth('bob'))).toEqual({
+            action: 'forbidden',
+        });
+
+        room.handleSetTeamsEnabled(
+            {
+                action: 'setTeamsEnabled',
+                payload: { enabled: true },
+            } as SetTeamsEnabledAction,
+        );
+        expect(updateTeamsEnabled).toHaveBeenCalledWith('room-id', true);
+        expect(room.handleJoinTeam(joinTeam, auth('bob'))?.action).toBe(
+            'joinedTeam',
+        );
+        expect(room.getTeamForPlayer('bob')).toBe(aliceTeam);
+    });
+
+    it('uses player names for single-player rooms and team names when enabled', () => {
+        const room = createRoom();
+        room.handleJoin(joinAction('Alice'), auth('alice'), socket());
+        const team = room.getTeamForPlayer('alice')!;
+
+        expect(room.getTeamDisplayName(team)).toBe('Alice');
+        room.handleSetTeamsEnabled(
+            {
+                action: 'setTeamsEnabled',
+                payload: { enabled: true },
+            } as SetTeamsEnabledAction,
+        );
+        expect(room.getTeamDisplayName(team)).toBe('Team Alice');
+    });
+});
\ No newline at end of file
diff --git a/api/src/tests/core/TeamPlayer.test.ts b/api/src/tests/core/TeamPlayer.test.ts
new file mode 100644
index 00000000..b1bfedb3
--- /dev/null
+++ b/api/src/tests/core/TeamPlayer.test.ts
@@ -0,0 +1,153 @@
+import { mock } from 'jest-mock-extended';
+import Player from '../../core/Player';
+import Room from '../../core/Room';
+import { RevealedCell } from '@playbingo/types';
+import Team from '../../core/Team';
+
+const room = mock<Room>();
+room.board = [Array(5).fill(mock<RevealedCell>()), [], [], [], []];
+
+const createTeam = () => new Team(room, 'test', 'Test Team');
+
+const createPlayer = (team?: Team) =>
+    new Player(
+        room,
+        'test',
+        'Test Player',
+        false,
+        team ? team.obfuscateBoard : room.spectatorObfuscateBoard,
+        team?.id,
+    );
+
+describe('Goal Tracking', () => {
+    beforeEach(() => {
+        room.exploration = false;
+    });
+
+    it('Correctly marks unmarked cells', () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        team.mark(0, 0);
+        expect(team.markedGoals).toEqual(1n);
+        expect(team.goalCount).toEqual(1);
+        team.mark(0, 4);
+        expect(team.markedGoals).toEqual(BigInt(0b10001));
+        expect(team.goalCount).toEqual(2);
+        team.mark(0, 3);
+        team.mark(1, 4);
+        expect(team.markedGoals).toEqual(BigInt(0b1000011001));
+        expect(team.goalCount).toEqual(4);
+    });
+
+    it("Doesn't change marked cells when marking a cell that is already marked", () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        team.mark(0, 0);
+        team.mark(1, 2);
+        const original = team.markedGoals;
+        team.mark(1, 2);
+        expect(team.markedGoals).toEqual(original);
+        expect(team.goalCount).toEqual(2);
+    });
+
+    it('Correctly unmarks marked cells', () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        team.mark(0, 0);
+        team.mark(1, 2);
+        team.mark(1, 4);
+        team.mark(2, 2);
+        team.mark(3, 0);
+        team.mark(3, 2);
+        team.unmark(2, 2);
+        expect(team.markedGoals).toEqual(BigInt(0b101000001010000001));
+        expect(team.goalCount).toEqual(5);
+        team.unmark(3, 2);
+        team.unmark(1, 4);
+        expect(team.goalCount).toEqual(3);
+        expect(team.markedGoals).toEqual(BigInt(0b1000000010000001));
+    });
+
+    it("Doesn't change marked cells when unmarking a cell that is not marked", () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        team.mark(0, 0);
+        team.mark(1, 3);
+        const original = team.markedGoals;
+        team.unmark(3, 0);
+        expect(team.markedGoals).toEqual(original);
+        expect(team.goalCount).toEqual(2);
+    });
+
+    it('Correctly tells if a cell is marked', () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        const toMark = [3, 7, 9, 16, 21];
+        const unmarked = Array.from(Array(25), (_, index) => index).filter(
+            (index) => !toMark.includes(index),
+        );
+        toMark.forEach((index) =>
+            team.mark(index % 5, Math.floor(index / 5)),
+        );
+        toMark.forEach((index) =>
+            expect(
+                team.hasMarked(index % 5, Math.floor(index / 5)),
+            ).toBeTruthy(),
+        );
+        unmarked.forEach((index) =>
+            expect(
+                team.hasMarked(index % 5, Math.floor(index / 5)),
+            ).toBeFalsy(),
+        );
+    });
+
+    it('Correctly determines if a set of goals is marked', () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        team.mark(0, 0);
+        team.mark(0, 1);
+        team.mark(0, 2);
+        team.mark(0, 3);
+        team.mark(0, 4);
+        team.mark(1, 0);
+        team.mark(2, 0);
+        team.mark(3, 0);
+        team.mark(4, 0);
+        const row1Mask = BigInt(0b11111);
+        const row2Mask = BigInt(0b1111100000);
+        const col1Mask = BigInt(0b0000100001000010000100001);
+        expect(team.hasCompletedGoals(row1Mask)).toBeTruthy();
+        expect(team.hasCompletedGoals(col1Mask)).toBeTruthy();
+        expect(team.hasCompletedGoals(row2Mask)).toBeFalsy();
+    });
+});
+
+describe('Exploration', () => {
+    beforeEach(() => {
+        room.exploration = true;
+        room.alwaysRevealedMask = 1n;
+    });
+
+    it('Correctly reveals cells when marking with exploration enabled', () => {
+        const team = createTeam();
+        const player = createPlayer(team);
+        team.room.exploration = true;
+        team.mark(2, 2);
+        expect(team.hasRevealed(1, 2)).toBeTruthy();
+        expect(team.hasRevealed(3, 2)).toBeTruthy();
+        expect(team.hasRevealed(2, 1)).toBeTruthy();
+        expect(team.hasRevealed(2, 3)).toBeTruthy();
+    });
+
+    it('Correctly hides cells when marking with exploration enabled', () => {
+        const team = createTeam();
+        team.room.exploration = true;
+        team.mark(2, 2);
+        team.unmark(2, 2);
+        expect(team.hasRevealed(1, 2)).toBeFalsy();
+        expect(team.hasRevealed(3, 2)).toBeFalsy();
+        expect(team.hasRevealed(2, 1)).toBeFalsy();
+        expect(team.hasRevealed(2, 3)).toBeFalsy();
+        expect(team.hasRevealed(2, 3)).toBeFalsy();
+    });
+});
diff --git a/api/src/tests/util/WinDetection.test.ts b/api/src/tests/util/WinDetection.test.ts
index 92bcc431..ddf3999d 100644
--- a/api/src/tests/util/WinDetection.test.ts
+++ b/api/src/tests/util/WinDetection.test.ts
@@ -23,7 +23,7 @@ const boardToBitset = (board: Cell[][], color: string) => {
     let bitset = 0n;
     board.forEach((row, rowIndex) =>
         row.forEach((cell, colIndex) => {
-            if (cell.completedPlayers.includes(color)) {
+            if (cell.completedTeams.includes(color)) {
                 bitset |= 1n << BigInt(rowIndex * board.length + colIndex);
             }
         }),
@@ -109,27 +109,27 @@ describe('Win Conditions', () => {
 
     it('Correctly detects single rows', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue'];
-        board[0][1].completedPlayers = ['blue'];
-        board[0][2].completedPlayers = ['blue'];
-        board[0][3].completedPlayers = ['blue'];
-        board[0][4].completedPlayers = ['blue'];
+        board[0][0].completedTeams = ['blue'];
+        board[0][1].completedTeams = ['blue'];
+        board[0][2].completedTeams = ['blue'];
+        board[0][3].completedTeams = ['blue'];
+        board[0][4].completedTeams = ['blue'];
         expect(countLines(board, 'blue')).toEqual(1);
         expect(countLines(board, 'red')).toEqual(0);
     });
 
     it('Correctly detects single rows with additional values on the board', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue', 'red'];
-        board[0][1].completedPlayers = ['blue'];
-        board[0][2].completedPlayers = ['blue'];
-        board[0][3].completedPlayers = ['red', 'blue', 'green'];
-        board[0][4].completedPlayers = ['blue'];
-        board[4][2].completedPlayers = ['red'];
-        board[4][3].completedPlayers = ['red', 'green'];
-        board[3][1].completedPlayers = ['blue', 'red', 'green'];
-        board[1][4].completedPlayers = ['blue', 'green'];
-        board[2][2].completedPlayers = ['green', 'blue'];
+        board[0][0].completedTeams = ['blue', 'red'];
+        board[0][1].completedTeams = ['blue'];
+        board[0][2].completedTeams = ['blue'];
+        board[0][3].completedTeams = ['red', 'blue', 'green'];
+        board[0][4].completedTeams = ['blue'];
+        board[4][2].completedTeams = ['red'];
+        board[4][3].completedTeams = ['red', 'green'];
+        board[3][1].completedTeams = ['blue', 'red', 'green'];
+        board[1][4].completedTeams = ['blue', 'green'];
+        board[2][2].completedTeams = ['green', 'blue'];
         expect(countLines(board, 'blue')).toEqual(1);
         expect(countLines(board, 'red')).toEqual(0);
         expect(countLines(board, 'green')).toEqual(0);
@@ -137,20 +137,20 @@ describe('Win Conditions', () => {
 
     it('Correctly detects multiple rows', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue', 'red'];
-        board[0][1].completedPlayers = ['blue'];
-        board[0][2].completedPlayers = ['blue'];
-        board[0][3].completedPlayers = ['red', 'blue', 'green'];
-        board[0][4].completedPlayers = ['blue'];
-        board[1][0].completedPlayers = ['red', 'blue'];
-        board[1][1].completedPlayers = ['blue', 'red'];
-        board[1][2].completedPlayers = ['blue'];
-        board[1][3].completedPlayers = ['blue'];
-        board[1][4].completedPlayers = ['blue', 'green'];
-        board[2][2].completedPlayers = ['green', 'blue'];
-        board[3][1].completedPlayers = ['blue', 'red', 'green'];
-        board[4][2].completedPlayers = ['red'];
-        board[4][3].completedPlayers = ['red', 'green'];
+        board[0][0].completedTeams = ['blue', 'red'];
+        board[0][1].completedTeams = ['blue'];
+        board[0][2].completedTeams = ['blue'];
+        board[0][3].completedTeams = ['red', 'blue', 'green'];
+        board[0][4].completedTeams = ['blue'];
+        board[1][0].completedTeams = ['red', 'blue'];
+        board[1][1].completedTeams = ['blue', 'red'];
+        board[1][2].completedTeams = ['blue'];
+        board[1][3].completedTeams = ['blue'];
+        board[1][4].completedTeams = ['blue', 'green'];
+        board[2][2].completedTeams = ['green', 'blue'];
+        board[3][1].completedTeams = ['blue', 'red', 'green'];
+        board[4][2].completedTeams = ['red'];
+        board[4][3].completedTeams = ['red', 'green'];
         expect(countLines(board, 'blue')).toEqual(2);
         expect(countLines(board, 'red')).toEqual(0);
         expect(countLines(board, 'green')).toEqual(0);
@@ -158,27 +158,27 @@ describe('Win Conditions', () => {
 
     it('Correctly detects single columns', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue'];
-        board[1][0].completedPlayers = ['blue'];
-        board[2][0].completedPlayers = ['blue'];
-        board[3][0].completedPlayers = ['blue'];
-        board[4][0].completedPlayers = ['blue'];
+        board[0][0].completedTeams = ['blue'];
+        board[1][0].completedTeams = ['blue'];
+        board[2][0].completedTeams = ['blue'];
+        board[3][0].completedTeams = ['blue'];
+        board[4][0].completedTeams = ['blue'];
         expect(countLines(board, 'blue')).toEqual(1);
         expect(countLines(board, 'red')).toEqual(0);
     });
 
     it('Correctly detects single column with additional values on the board', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue'];
-        board[1][0].completedPlayers = ['blue', 'red'];
-        board[2][0].completedPlayers = ['green', 'blue'];
-        board[3][0].completedPlayers = ['blue'];
-        board[4][0].completedPlayers = ['blue', 'red', 'green'];
-        board[4][2].completedPlayers = ['red'];
-        board[4][3].completedPlayers = ['red', 'green'];
-        board[3][1].completedPlayers = ['blue', 'red', 'green'];
-        board[1][4].completedPlayers = ['blue', 'green'];
-        board[2][2].completedPlayers = ['green', 'blue'];
+        board[0][0].completedTeams = ['blue'];
+        board[1][0].completedTeams = ['blue', 'red'];
+        board[2][0].completedTeams = ['green', 'blue'];
+        board[3][0].completedTeams = ['blue'];
+        board[4][0].completedTeams = ['blue', 'red', 'green'];
+        board[4][2].completedTeams = ['red'];
+        board[4][3].completedTeams = ['red', 'green'];
+        board[3][1].completedTeams = ['blue', 'red', 'green'];
+        board[1][4].completedTeams = ['blue', 'green'];
+        board[2][2].completedTeams = ['green', 'blue'];
         expect(countLines(board, 'blue')).toEqual(1);
         expect(countLines(board, 'red')).toEqual(0);
         expect(countLines(board, 'green')).toEqual(0);
@@ -186,19 +186,19 @@ describe('Win Conditions', () => {
 
     it('Correctly detects multiple columns', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue'];
-        board[1][0].completedPlayers = ['blue', 'red'];
-        board[2][0].completedPlayers = ['green', 'blue'];
-        board[3][0].completedPlayers = ['blue'];
-        board[4][0].completedPlayers = ['blue', 'red', 'green'];
-        board[0][3].completedPlayers = ['blue'];
-        board[1][3].completedPlayers = ['blue', 'red'];
-        board[2][3].completedPlayers = ['green', 'blue'];
-        board[3][3].completedPlayers = ['blue'];
-        board[4][3].completedPlayers = ['blue', 'red', 'green'];
-        board[2][2].completedPlayers = ['green', 'blue'];
-        board[3][1].completedPlayers = ['blue', 'red', 'green'];
-        board[4][2].completedPlayers = ['red'];
+        board[0][0].completedTeams = ['blue'];
+        board[1][0].completedTeams = ['blue', 'red'];
+        board[2][0].completedTeams = ['green', 'blue'];
+        board[3][0].completedTeams = ['blue'];
+        board[4][0].completedTeams = ['blue', 'red', 'green'];
+        board[0][3].completedTeams = ['blue'];
+        board[1][3].completedTeams = ['blue', 'red'];
+        board[2][3].completedTeams = ['green', 'blue'];
+        board[3][3].completedTeams = ['blue'];
+        board[4][3].completedTeams = ['blue', 'red', 'green'];
+        board[2][2].completedTeams = ['green', 'blue'];
+        board[3][1].completedTeams = ['blue', 'red', 'green'];
+        board[4][2].completedTeams = ['red'];
         expect(countLines(board, 'blue')).toEqual(2);
         expect(countLines(board, 'red')).toEqual(0);
         expect(countLines(board, 'green')).toEqual(0);
@@ -206,53 +206,53 @@ describe('Win Conditions', () => {
 
     it('Correctly detects the main diagonal', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue'];
-        board[1][1].completedPlayers = ['blue'];
-        board[2][2].completedPlayers = ['blue'];
-        board[3][3].completedPlayers = ['blue'];
-        board[4][4].completedPlayers = ['blue'];
+        board[0][0].completedTeams = ['blue'];
+        board[1][1].completedTeams = ['blue'];
+        board[2][2].completedTeams = ['blue'];
+        board[3][3].completedTeams = ['blue'];
+        board[4][4].completedTeams = ['blue'];
         expect(countLines(board, 'blue')).toEqual(1);
         expect(countLines(board, 'red')).toEqual(0);
     });
 
     it('Correctly detects the antiDiagonal', () => {
         const board = createBoard();
-        board[0][4].completedPlayers = ['blue'];
-        board[1][3].completedPlayers = ['blue'];
-        board[2][2].completedPlayers = ['blue'];
-        board[3][1].completedPlayers = ['blue'];
-        board[4][0].completedPlayers = ['blue'];
+        board[0][4].completedTeams = ['blue'];
+        board[1][3].completedTeams = ['blue'];
+        board[2][2].completedTeams = ['blue'];
+        board[3][1].completedTeams = ['blue'];
+        board[4][0].completedTeams = ['blue'];
         expect(countLines(board, 'blue')).toEqual(1);
         expect(countLines(board, 'red')).toEqual(0);
     });
 
     it('Correctly detects mixed lines and colors', () => {
         const board = createBoard();
-        board[0][0].completedPlayers = ['blue', 'green'];
-        board[0][1].completedPlayers = ['blue', 'red', 'green'];
-        board[0][2].completedPlayers = ['green', 'blue'];
-        board[0][3].completedPlayers = ['blue', 'green'];
-        board[0][4].completedPlayers = [
+        board[0][0].completedTeams = ['blue', 'green'];
+        board[0][1].completedTeams = ['blue', 'red', 'green'];
+        board[0][2].completedTeams = ['green', 'blue'];
+        board[0][3].completedTeams = ['blue', 'green'];
+        board[0][4].completedTeams = [
             'blue',
             'red',
             'green',
             'yellow',
             'orange',
         ];
-        board[1][0].completedPlayers = ['blue', 'red', 'orange'];
-        board[2][0].completedPlayers = ['green', 'blue'];
-        board[3][0].completedPlayers = ['blue'];
-        board[4][0].completedPlayers = ['blue', 'yellow', 'green', 'orange'];
-        board[1][1].completedPlayers = ['blue', 'red', 'green'];
-        board[2][2].completedPlayers = ['green'];
-        board[3][3].completedPlayers = ['red', 'green'];
-        board[4][4].completedPlayers = ['blue', 'red', 'green'];
-        board[1][3].completedPlayers = ['blue', 'red'];
-        board[2][3].completedPlayers = ['green', 'blue'];
-        board[4][3].completedPlayers = ['blue', 'red', 'green'];
-        board[3][1].completedPlayers = ['blue', 'red', 'green'];
-        board[4][2].completedPlayers = ['red', 'yellow'];
-        board[4][3].completedPlayers = ['red', 'green', 'orange'];
+        board[1][0].completedTeams = ['blue', 'red', 'orange'];
+        board[2][0].completedTeams = ['green', 'blue'];
+        board[3][0].completedTeams = ['blue'];
+        board[4][0].completedTeams = ['blue', 'yellow', 'green', 'orange'];
+        board[1][1].completedTeams = ['blue', 'red', 'green'];
+        board[2][2].completedTeams = ['green'];
+        board[3][3].completedTeams = ['red', 'green'];
+        board[4][4].completedTeams = ['blue', 'red', 'green'];
+        board[1][3].completedTeams = ['blue', 'red'];
+        board[2][3].completedTeams = ['green', 'blue'];
+        board[4][3].completedTeams = ['blue', 'red', 'green'];
+        board[3][1].completedTeams = ['blue', 'red', 'green'];
+        board[4][2].completedTeams = ['red', 'yellow'];
+        board[4][3].completedTeams = ['red', 'green', 'orange'];
         expect(countLines(board, 'blue')).toEqual(2);
         expect(countLines(board, 'red')).toEqual(0);
         expect(countLines(board, 'green')).toEqual(2);
diff --git a/api/src/util/RoomUtils.ts b/api/src/util/RoomUtils.ts
index 108f3b6b..6166f5f5 100644
--- a/api/src/util/RoomUtils.ts
+++ b/api/src/util/RoomUtils.ts
@@ -10,7 +10,7 @@ export const listToBoard = (
     return chunk(
         list.map((g) => ({
             goal: g,
-            completedPlayers: [],
+            completedTeams: [],
             revealed: true,
         })),
         length,
diff --git a/schema/index.d.ts b/schema/index.d.ts
index f442ad54..3bc40be4 100644
--- a/schema/index.d.ts
+++ b/schema/index.d.ts
@@ -10,4 +10,5 @@ export * from './types/Player';
 export * from './types/RoomAction';
 export * from './types/RoomData';
 export * from './types/ServerMessage';
+export * from './types/Team';
 export * from './types/User';
diff --git a/schema/package-lock.json b/schema/package-lock.json
index a76450c2..4e6456c8 100644
--- a/schema/package-lock.json
+++ b/schema/package-lock.json
@@ -570,6 +570,7 @@
       "integrity": "sha512-FE5u0ezmi6y9OZEzlJfg37mqqf6ZDSF2V/NLjUyGrR9uTZ7Sb9F7bLNZ03S4XVUNRWGA7Ck4c1kK+YnuWjl+DA==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "undici-types": "~6.21.0"
       }
@@ -800,6 +801,7 @@
       "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.4.tgz",
       "integrity": "sha512-QP88BAKvMam/3NxH6vj2o21R6MjxZUAd6nlwAS/pnGvN9IVLocLHxGYIzFhg6fUQ+5th6P4dv4eW9jX3DSIj7A==",
       "license": "MIT",
+      "peer": true,
       "engines": {
         "node": ">=12"
       },
@@ -918,6 +920,7 @@
       "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==",
       "dev": true,
       "license": "Apache-2.0",
+      "peer": true,
       "bin": {
         "tsc": "bin/tsc",
         "tsserver": "bin/tsserver"
diff --git a/schema/schemas/Cell.json b/schema/schemas/Cell.json
index b6a94909..5a9ee64f 100644
--- a/schema/schemas/Cell.json
+++ b/schema/schemas/Cell.json
@@ -2,7 +2,7 @@
     "$schema": "https://json-schema.org/draft/2020-12/schema",
     "type": "object",
     "additionalProperties": false,
-    "required": ["goal", "description", "completedPlayers"],
+    "required": ["goal", "description", "completedTeams"],
     "anyOf": [
         {"$ref": "#/$defs/RevealedCell"},
         {"$ref": "#/$defs/HiddenCell"}
@@ -10,19 +10,19 @@
     "$defs": {
         "RevealedCell": {
             "additionalProperties": false,
-            "required": ["revealed", "goal", "completedPlayers"],
+            "required": ["revealed", "goal", "completedTeams"],
             "properties": {
                 "goal": {"$ref": "./Goal.json"},
-                "completedPlayers": {"type": "array", "items": {"type": "string"}},
+                "completedTeams": {"type": "array", "items": {"type": "string"}},
                 "revealed": { "enum": [ true ]}
             }
         },
         "HiddenCell": {
             "additionalProperties": false,
-            "required": ["revealed", "completedPlayers"],
+            "required": ["revealed", "completedTeams"],
             "properties": {
                 "revealed": { "enum": [ false ]},
-                "completedPlayers": {"type": "array", "items": {"type": "string"}}
+                "completedTeams": {"type": "array", "items": {"type": "string"}}
             }
         }
     }
diff --git a/schema/schemas/Player.json b/schema/schemas/Player.json
index f1c83918..9b0bb218 100644
--- a/schema/schemas/Player.json
+++ b/schema/schemas/Player.json
@@ -5,12 +5,10 @@
     "required": [
         "id",
         "nickname",
-        "color",
-        "goalCount",
         "raceStatus",
-        "spectator",
         "monitor",
-        "showInRoom"
+        "showInRoom",
+        "teamId"
     ],
     "properties": {
         "id": {
@@ -19,12 +17,6 @@
         "nickname": {
             "type": "string"
         },
-        "color": {
-            "type": "string"
-        },
-        "goalCount": {
-            "type": "number"
-        },
         "raceStatus": {
             "oneOf": [
                 {
@@ -35,14 +27,14 @@
                 }
             ]
         },
-        "spectator": {
-            "type": "boolean"
-        },
         "monitor": {
             "type": "boolean"
         },
         "showInRoom": {
             "type": "boolean"
+        },
+        "teamId": {
+            "type": "string"
         }
     },
     "$defs": {
diff --git a/schema/schemas/RoomAction.json b/schema/schemas/RoomAction.json
index b4253362..174cdace 100644
--- a/schema/schemas/RoomAction.json
+++ b/schema/schemas/RoomAction.json
@@ -10,6 +10,7 @@
     "anyOf": [
         {"$ref": "#/$defs/JoinAction"},
         {"$ref": "#/$defs/LeaveAction"},
+        {"$ref": "#/$defs/JoinTeamAction"},
         {"$ref": "#/$defs/ChatAction"},
         {"$ref": "#/$defs/MarkAction"},
         {"$ref": "#/$defs/UnmarkAction"},
@@ -20,7 +21,8 @@
         {"$ref": "#/$defs/StartTimerAction"},
         {"$ref": "#/$defs/ChangeRaceHandlerAction"},
         {"$ref": "#/$defs/ResetTimerAction"},
-        {"$ref": "#/$defs/SetChatEnabledAction"}
+        {"$ref": "#/$defs/SetChatEnabledAction"},
+        {"$ref": "#/$defs/SetTeamsEnabledAction"}
     ],
     "$defs": {
         "JoinAction": {
@@ -44,6 +46,20 @@
                 "action": "leave"
             }
         },
+        "JoinTeamAction": {
+            "required": ["action", "payload"],
+            "additionalProperties": false,
+            "properties": {
+                "action": "joinTeam",
+                "payload": {
+                    "required": ["teamId"],
+                    "additionalProperties": false,
+                    "properties": {
+                        "teamId": {"type": "string"}
+                    }
+                }
+            }
+        },
         "ChatAction": {
             "required": ["action", "payload"],
             "additionalProperties": false,
@@ -174,6 +190,20 @@
                     }
                 }
             }
+        },
+        "SetTeamsEnabledAction": {
+            "required": ["action", "payload"],
+            "additionalProperties": false,
+            "properties": {
+                "action": "setTeamsEnabled",
+                "payload": {
+                    "required": ["enabled"],
+                    "additionalProperties": false,
+                    "properties": {
+                        "enabled": {"type": "boolean"}
+                    }
+                }
+            }
         }
     }
 }
\ No newline at end of file
diff --git a/schema/schemas/RoomData.json b/schema/schemas/RoomData.json
index fd7b770b..7812157d 100644
--- a/schema/schemas/RoomData.json
+++ b/schema/schemas/RoomData.json
@@ -10,7 +10,8 @@
         "newGenerator",
         "variant",
         "mode",
-        "seed"
+        "seed",
+        "teamsEnabled"
     ],
     "description": "Basic information about a room",
     "properties": {
@@ -45,6 +46,9 @@
         "seed": {
             "type": "number"
         },
+        "teamsEnabled": {
+            "type": "boolean"
+        },
         "startedAt": {
             "type": "string"
         },
diff --git a/schema/schemas/ServerMessage.json b/schema/schemas/ServerMessage.json
index 280b350d..acca85db 100644
--- a/schema/schemas/ServerMessage.json
+++ b/schema/schemas/ServerMessage.json
@@ -6,9 +6,20 @@
     "description": "An incoming websocket message from the server telling the client of a change in room state or instructing it to take an action",
     "properties": {
         "players": {
-            "type": "array",
-            "items": {
-                "$ref": "./Player.json"
+            "type": "object",
+            "additionalProperties": false,
+            "required": ["teams", "spectators"],
+            "properties": {
+                "teams": {
+                    "items": {
+                        "$ref": "./Team.json"
+                    }
+                },
+                "spectators": {
+                    "items": {
+                        "$ref": "./Player.json"
+                    }
+                }
             }
         },
         "connectedPlayer": {
@@ -29,6 +40,19 @@
                 }
             }
         },
+        {
+            "required": [
+                "action",
+                "team"
+            ],
+            "additionalProperties": false,
+            "properties": {
+                "action": "joinedTeam",
+                "team": {
+                    "$ref": "./Team.json"
+                }
+            }
+        },
         {
             "required": [
                 "action",
@@ -133,9 +157,20 @@
             "properties": {
                 "action": "syncRaceData",
                 "players": {
-                    "type": "array",
-                    "items": {
-                        "$ref": "./Player.json"
+                    "type": "object",
+                    "additionalProperties": false,
+                    "required": ["teams", "spectators"],
+                    "properties": {
+                        "teams": {
+                            "items": {
+                                "$ref": "./Team.json"
+                            }
+                        },
+                        "spectators": {
+                            "items": {
+                                "$ref": "./Player.json"
+                            }
+                        }
                     }
                 },
                 "racetimeConnection": {
diff --git a/schema/schemas/Team.json b/schema/schemas/Team.json
new file mode 100644
index 00000000..03a48144
--- /dev/null
+++ b/schema/schemas/Team.json
@@ -0,0 +1,32 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "object",
+    "additionalProperties": false,
+    "required": [
+        "id",
+        "name",
+        "color",
+        "goalCount",
+        "players"
+    ],
+    "properties": {
+        "id": {
+            "type": "string"
+        },
+        "name": {
+            "type": "string"
+        },
+        "color": {
+            "type": "string"
+        },
+        "goalCount": {
+            "type": "number"
+        },
+        "players": {
+            "type": "array",
+            "items": {
+                "$ref": "./Player.json"
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/schema/types/Board.d.ts b/schema/types/Board.d.ts
index b2fa3bed..31d18c6a 100644
--- a/schema/types/Board.d.ts
+++ b/schema/types/Board.d.ts
@@ -16,7 +16,7 @@ export interface RevealedBoard {
 }
 export interface RevealedCell {
   goal: Goal;
-  completedPlayers: string[];
+  completedTeams: string[];
   revealed: true;
 }
 /**
@@ -55,7 +55,7 @@ export interface GoalTag {
 }
 export interface HiddenCell {
   revealed: false;
-  completedPlayers: string[];
+  completedTeams: string[];
 }
 export interface HiddenBoard {
   hidden: true;
diff --git a/schema/types/Cell.d.ts b/schema/types/Cell.d.ts
index 3a48cf41..8f35052b 100644
--- a/schema/types/Cell.d.ts
+++ b/schema/types/Cell.d.ts
@@ -9,7 +9,7 @@ export type Cell = RevealedCell | HiddenCell;
 
 export interface RevealedCell {
   goal: Goal;
-  completedPlayers: string[];
+  completedTeams: string[];
   revealed: true;
 }
 /**
@@ -48,5 +48,5 @@ export interface GoalTag {
 }
 export interface HiddenCell {
   revealed: false;
-  completedPlayers: string[];
+  completedTeams: string[];
 }
diff --git a/schema/types/Player.d.ts b/schema/types/Player.d.ts
index e560db70..8530bae0 100644
--- a/schema/types/Player.d.ts
+++ b/schema/types/Player.d.ts
@@ -8,12 +8,10 @@
 export interface Player {
   id: string;
   nickname: string;
-  color: string;
-  goalCount: number;
   raceStatus: RaceStatusDisconnected | RaceStatusConnected;
-  spectator: boolean;
   monitor: boolean;
   showInRoom: boolean;
+  teamId: string;
 }
 export interface RaceStatusDisconnected {
   connected: false;
diff --git a/schema/types/RoomAction.d.ts b/schema/types/RoomAction.d.ts
index 0566e324..5bb6753a 100644
--- a/schema/types/RoomAction.d.ts
+++ b/schema/types/RoomAction.d.ts
@@ -11,6 +11,7 @@
 export type RoomAction = (
   | JoinAction
   | LeaveAction
+  | JoinTeamAction
   | ChatAction
   | MarkAction
   | UnmarkAction
@@ -22,6 +23,7 @@ export type RoomAction = (
   | ChangeRaceHandlerAction
   | ResetTimerAction
   | SetChatEnabledAction
+  | SetTeamsEnabledAction
 ) & {
   /**
    * JWT for the room obtained from the server
@@ -38,6 +40,12 @@ export interface JoinAction {
 export interface LeaveAction {
   action: "leave";
 }
+export interface JoinTeamAction {
+  action: "joinTeam";
+  payload: {
+    teamId: string;
+  };
+}
 export interface ChatAction {
   action: "chat";
   payload: {
@@ -97,3 +105,9 @@ export interface SetChatEnabledAction {
     enabled: boolean;
   };
 }
+export interface SetTeamsEnabledAction {
+  action: "setTeamsEnabled";
+  payload: {
+    enabled: boolean;
+  };
+}
diff --git a/schema/types/RoomData.d.ts b/schema/types/RoomData.d.ts
index 7e4352e4..e1f6a59d 100644
--- a/schema/types/RoomData.d.ts
+++ b/schema/types/RoomData.d.ts
@@ -22,6 +22,7 @@ export interface RoomData {
   variant: string;
   mode: string;
   seed: number;
+  teamsEnabled: boolean;
   startedAt?: string;
   finishedAt?: string;
   raceHandler?: "LOCAL" | "RACETIME";
diff --git a/schema/types/ServerMessage.d.ts b/schema/types/ServerMessage.d.ts
index 00beadc0..15395589 100644
--- a/schema/types/ServerMessage.d.ts
+++ b/schema/types/ServerMessage.d.ts
@@ -13,6 +13,10 @@ export type ServerMessage = (
       action: "chat";
       message: ChatMessage;
     }
+  | {
+      action: "joinedTeam";
+      team: Team;
+    }
   | {
       action: "cellUpdate";
       row: number;
@@ -42,7 +46,10 @@ export type ServerMessage = (
     }
   | {
       action: "syncRaceData";
-      players: Player[];
+      players: {
+        teams: Team[];
+        spectators: Player[];
+      };
       racetimeConnection: RacetimeConnection;
     }
   | {
@@ -57,7 +64,10 @@ export type ServerMessage = (
       startTime: string;
     }
 ) & {
-  players?: Player[];
+  players?: {
+    teams: Team[];
+    spectators: Player[];
+  };
   connectedPlayer?: Player;
 };
 export type ChatMessage = (
@@ -70,9 +80,39 @@ export type ChatMessage = (
 export type Cell = RevealedCell | HiddenCell;
 export type Board = RevealedBoard | HiddenBoard;
 
+export interface Team {
+  id: string;
+  name: string;
+  color: string;
+  goalCount: number;
+  players: Player[];
+}
+export interface Player {
+  id: string;
+  nickname: string;
+  raceStatus: RaceStatusDisconnected | RaceStatusConnected;
+  monitor: boolean;
+  showInRoom: boolean;
+  teamId: string;
+}
+export interface RaceStatusDisconnected {
+  connected: false;
+}
+export interface RaceStatusConnected {
+  connected: true;
+  /**
+   * Username connected to this player for the race, if it is separate from PlayBingo
+   */
+  username: string;
+  ready?: boolean;
+  /**
+   * Race finish time (ISO 8601 duration)
+   */
+  finishTime?: string;
+}
 export interface RevealedCell {
   goal: Goal;
-  completedPlayers: string[];
+  completedTeams: string[];
   revealed: true;
 }
 /**
@@ -111,7 +151,7 @@ export interface GoalTag {
 }
 export interface HiddenCell {
   revealed: false;
-  completedPlayers: string[];
+  completedTeams: string[];
 }
 export interface RevealedBoard {
   board: Cell[][];
@@ -141,6 +181,7 @@ export interface RoomData {
   variant: string;
   mode: string;
   seed: number;
+  teamsEnabled: boolean;
   startedAt?: string;
   finishedAt?: string;
   raceHandler?: "LOCAL" | "RACETIME";
@@ -168,28 +209,3 @@ export interface RacetimeConnection {
    */
   startDelay?: string;
 }
-export interface Player {
-  id: string;
-  nickname: string;
-  color: string;
-  goalCount: number;
-  raceStatus: RaceStatusDisconnected | RaceStatusConnected;
-  spectator: boolean;
-  monitor: boolean;
-  showInRoom: boolean;
-}
-export interface RaceStatusDisconnected {
-  connected: false;
-}
-export interface RaceStatusConnected {
-  connected: true;
-  /**
-   * Username connected to this player for the race, if it is separate from PlayBingo
-   */
-  username: string;
-  ready?: boolean;
-  /**
-   * Race finish time (ISO 8601 duration)
-   */
-  finishTime?: string;
-}
diff --git a/schema/types/Team.d.ts b/schema/types/Team.d.ts
new file mode 100644
index 00000000..50f82289
--- /dev/null
+++ b/schema/types/Team.d.ts
@@ -0,0 +1,37 @@
+/* eslint-disable */
+/**
+ * This file was automatically generated by json-schema-to-typescript.
+ * DO NOT MODIFY IT BY HAND. Instead, modify the source JSONSchema file,
+ * and run json-schema-to-typescript to regenerate this file.
+ */
+
+export interface Team {
+  id: string;
+  name: string;
+  color: string;
+  goalCount: number;
+  players: Player[];
+}
+export interface Player {
+  id: string;
+  nickname: string;
+  raceStatus: RaceStatusDisconnected | RaceStatusConnected;
+  monitor: boolean;
+  showInRoom: boolean;
+  teamId: string;
+}
+export interface RaceStatusDisconnected {
+  connected: false;
+}
+export interface RaceStatusConnected {
+  connected: true;
+  /**
+   * Username connected to this player for the race, if it is separate from PlayBingo
+   */
+  username: string;
+  ready?: boolean;
+  /**
+   * Race finish time (ISO 8601 duration)
+   */
+  finishTime?: string;
+}