Turing Machine

A digital adaptation of the acclaimed deduction board game — with infinite procedurally generated puzzles and additional validators beyond the tabletop original.

Crack the code. One verifier at a time.

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What is this?

Turing Machine is a pen-and-paper-meets-logic-puzzle board game designed by Fabien Gridel and Yoann Levet, published by Le Scorpion Masqué. A secret three-digit code is hiding behind a set of verifiers. Each verifier knows one property of the code — something like "first digit is greater than 3" or "sum of the digits is less than 12". None of them reveals the code directly. Only by combining every verifier's hint does exactly one code survive.

This project is a fan-made digital adaptation built in Java with libGDX. It runs on Windows, Linux, macOS, Android, and directly in the browser via TeaVM.

Why play the digital version?

Feature	Tabletop	This project
Curated puzzle book	✓	✓
Infinite generated levels	—	✓
Extra validator families	—	✓
Auto-tracked deduction sheet	—	✓
Plays anywhere, instantly	—	✓
Smell of fresh cardboard	✓	—

How to play

A secret three-digit code is hidden. Each digit is between 1 and 5. Around it sits a handful of verifiers, each guarding one rule about the code.

Each round:

1. You enter a guess — any triple from 1 1 1 to 5 5 5.
2. You pick up to three verifiers to question.
3. Each verifier compares your guess against its own secret rule about the code and hands back a hint, not an answer. Examples of what you might see:
   • first > 3 — the first digit of the code is greater than 3
   • sum < 12 — the digits of the code add up to less than 12
   • second = 4 — the middle digit of the code equals 4
   • third is even — the last digit of the code is even
4. No single hint solves the puzzle. You cross-reference, eliminate, and slowly box the code in.
5. When only one code remains consistent with every hint, you submit it.

The goal: crack the code in as few rounds and as few verifier tests as possible. Puzzles are designed so that exactly one code satisfies every verifier — no luck, no randomness, pure deduction.

Running it

Requires JDK 17 on your PATH.

# Desktop (LWJGL3)
./gradlew desktop:run

# Browser (TeaVM, starts a local Jetty server)
./gradlew teavm:run

# Browser (release build, static files in teavm/build/dist)
./gradlew teavm:buildRelease

# Android — open the project in Android Studio and run the `android` module

On Windows use gradlew.bat instead of ./gradlew.

Tech stack

• libGDX 1.14.0 — rendering, input, cross-platform game loop
• gdx-teavm 1.5.3 — compiles Java straight to JavaScript, no GWT
• Java 17 — across all modules
• Gradle 8.13 — build tool
• Android Gradle Plugin 8.12 (minSdk 28, targetSdk 35)

Project layout

core/     Platform-independent game code (the interesting stuff)
desktop/  LWJGL3 launcher
android/  Android launcher + manifest
teavm/    Web launcher — compiles core to JS
assets/   Fonts, images, i18n bundles (shared across platforms)

Credits

• Turing Machine the board game was created by Fabien Gridel & Yoann Levet, published by Le Scorpion Masqué. Go buy a copy — it's genuinely great.
• Digital adaptation by Dirk Aporius.
• Built with libGDX and gdx-teavm.

License

This is a fan project, not affiliated with or endorsed by Le Scorpion Masqué. Code is provided as-is under the BSD-style notice in the source headers.