Main Street: PRD Milestone 1 -- Playable Core Loop (Walking Skeleton)

[SorraTheOrc]

Summary

Write the first incremental PRD for Main Street that delivers the absolute minimum playable version of the game -- the walking skeleton. This milestone proves the core loop works and is fun before investing in content, polish, or advanced features.

User Story

As a producer, I want a PRD for Main Street's minimum playable core loop so that the team can build and validate the fundamental game experience before expanding scope.

Prerequisites

• Main Street: GDD Review and Consolidation (CG-0MM4RDIMT1HLP2DE) completed and approved

PRD Scope

This PRD should cover the implementation of:

1. Game state model -- The TypeScript types/interfaces for Main Street's complete game state
2. Basic card types -- A minimal subset of cards (enough to demonstrate the core loop, not the full content)
3. Turn structure -- The fundamental turn/round flow
4. Core actions -- The 2-3 most essential player actions that define Main Street
5. Win/Loss detection -- Basic end-game detection
6. Minimal UI -- Placeholder-art UI that lets a human play Main Street (cards visible, actions clickable, state displayed)
7. Basic rules enforcement -- Legal move validation for core actions
8. Seeded RNG -- Deterministic randomness for reproducible games
9. Test suite -- Unit tests for rules, state transitions, and win/loss detection

PRD Document Structure

The PRD should include:

• Goal and success criteria
• Scope (what is IN and what is explicitly OUT)
• Detailed user stories with acceptance criteria
• Technical design notes (which engine components to use/extend)
• Asset requirements (placeholder art specs)
• Test plan
• Estimated effort (using three-point estimation if effort_and_risk skill is available)
• Dependencies and risks

Acceptance Criteria

1. PRD clearly defines Main Street's MVP scope with explicit in/out boundaries
2. All user stories have testable acceptance criteria
3. Technical approach references specific engine modules
4. A player could complete a full session of Main Street with only this milestone implemented
5. The core loop is identifiable and evaluable for fun factor
6. PRD is reviewed and approved by the producer

Related work (automated report)

• CG-0MM4R9UJF1DGI0ZF — Main Street (epic): Parent epic that groups all PRDs and GDD work; provides the high-level goals, scope, and acceptance criteria that this PRD should align to.
• CG-0MM4RDIMT1HLP2DE — Main Street: GDD Review and Consolidation (completed): Consolidated GDD that this PRD lists as a prerequisite; contains the authoritative game design that the PRD should reference for unambiguous rules and card definitions.
• CG-0MM4RC1K81JU4U5D — Main Street: GDD -- Core Rules and Mechanics (completed): Core rules document that specifies game state, turn structure, card anatomy, and win/loss conditions — directly relevant when drafting the PRD's technical design and acceptance criteria.
• CG-0MM4RAT5L12FHWKP — Main Street: Engine Capabilities Audit (completed): Audit documenting current engine features, recommended minor extensions, and major gaps (see docs/games/the-build/engine-capabilities-audit.md). Use this to decide which engine modules to reuse vs extend for the walking skeleton.
• CG-0MM5ZG63Q083JFV6 — Grid & Tile System (open): Feature proposal for a deterministic grid/tile abstraction; include for consideration only if Main Street's core loop requires spatial placement or tile mechanics.

(Automated report generated and appended by find_related tool.)