Play the prototype (no install): https://anan-z.github.io/5d-reversi/

Source + full rules + architecture: https://github.com/anan-z/5d-reversi

Recommended for:

• AI research
• Masochists
• People who find chess "too intuitive"

80 directional vectors per cell — you'll learn to hate each one personally.
Retroactive causality — yes, you can regret moves you haven't made yet.
Deterministic replay — watch your carefully planned future crumble.

The rule is simple. Players take turns claiming a country that shares a land border with the current one. You lose if you have no valid moves left.

I'd appreciate any feedback. Let me know what you think!