Hex Truchet

A hex-grid Truchet-tile placement game, developed from geometry research through bot design to a playable Godot game.

▶ Play it in your browser

Players alternate placing hexagonal tiles carrying curved paths onto a shared board. Adjacent tile edges connect, and closing a loop scores points for whoever completes it. The core design question driving this project was whether a simple greedy strategy is already close to optimal play, or whether there's real strategic depth to exploit — see hex_truchet/spec.md for the full rules.

docs/ holds the long-form write-up as an interactive article — the deck-tuning findings, three failed attempts to beat greedy with learning, and the search bot that finally did it. Every board and figure in it is generated from the real engine by viz/build_article_data.py; open docs/index.html over a local server (it fetches data.js).

Play it

The playable build is on itch.io: https://orbitope.itch.io/hex-truchet

The Godot project (hextruchet-godot/) has hot-seat, vs-bot, and replay modes. To run the web build locally:

cd hextruchet-godot/build/web
python3 -m http.server 8000

Then open http://localhost:8000/index.html. (If build/web/ doesn't exist yet, export it first from the Godot editor, or headless via godot --headless --export-release "Web" build/web/index.html.)

To run in the editor: open hextruchet-godot/ in Godot 4.7+.

Repo layout

• hex_truchet/ — the validated Python game engine and RL environment (rules, scoring, loop detection), built on the simulacrum environment framework. This is the reference implementation the Godot rules engine was differentially tested against.
• hextruchet-godot/ — the playable Godot 4 game: native GDScript rules engine, renderer, hot-seat/vs-bot/replay modes, and search-based bots.
• training/ — bot development and evaluation: the tunable rollout-search bots (bots.py), sweeps against a greedy baseline, and RL training experiments.
• viz/ — arc-rendering math and an HTML board viewer used to validate tile geometry before it was ported into Godot.
• hextruchet_first_pass/ — early-stage geometry, scoring, and agent research that shaped the final ruleset.

Status

Core gameplay (hot-seat, vs-bot, and free-placement modes; rule variants; tile rendering) is implemented and has been verified working, including in a browser-based web export. Difficulty balancing against human players is still unverified — the bot presets are currently tuned for strength, not for a fair fight against a casual player.