COHERENCE: Braid – Quantum Game Jam

This weekend we made a game in 48 hours for the Global Quantum Game Jam 2026.

The theme was quantum braiding. COHERENCE: Braid is a small civilization game with a twist: you do not build your civilization, you ask it questions, and you braid it. Your people are cohorts drawn as pairs of worldlines. Braiding two of them changes what the people are without anyone deciding anything. Asking a question forces a definite answer into existence, and it costs coherence, the only score there is. Lose it and the civilization collapses; only its myths survive into the next level.

In the last levels, two civilizations prove their alliance is real with a Bell test that no prior agreement can fake.

Underneath the story is real physics, not flavour text. Every cohort is a qubit, the civilization is a density matrix simulated exactly, the crossings are the Ising-anyon representation of the braid group, and the first random draws of each session come from Moth Quantum’s engines, with their entropy certificate and CHSH witness shown in the game verbatim. You can even eject your civilization’s braid as an OpenQASM 3 circuit.

Nine levels, about twenty minutes, works on a phone or a laptop, with a Stuck? button that explains the next move and will make it for you if you like.

PLAY NOW (free, in your browser): https://coherence-braid.spinsphere.xyz/

Trailer: https://www.youtube.com/watch?v=B_tO41rcZ_4
Source (MIT): https://github.com/spinsphere/coherence-braid-game