Critical Window

Play it right here in your browser, or at criticalwindow.org. Free, no account, no ads, no tracking. A run takes 20 to 40 minutes, works on phones, and the core game keeps working offline after the first load.

Summer 2026. You take office holding the AI race portfolio, sixteen quarterly turns to 2030. Each quarter you split your effort between capability, safety, and diffusion, then the world answers: memos with no clean options, incidents that leak the truth your eval reports smoothed over, a rival whose posture you can read but whose progress you can only watch. Five endings, and the good ones are earned.

Two dice were sealed in an envelope before you sat down: how hard alignment really is, and how fast capability compounds. Your eval reports are honest ranges, not answers. When the run ends, the debrief opens the envelope and draws what your evals said each quarter against what was actually true. Losing tells you exactly why.

Three ways to play. Solo as the United States. Solo as China, where the chips are scarce but the power is not. Hotseat: two people, one device, one shared world, two private screens.

Every number translates to something real. Compute 700 is about two-thirds of 2026 frontier training capacity. Capability 350 is systems that handle hour-scale expert tasks. The anchors come from published research, and the game shows you which. Every value in the game's data cites a source, the build fails when one does not, and the whole evidence map is browsable in the game, two clicks from the title screen. If you think a number is wrong, open a "challenge a number" issue with a better source. That argument is the project working as designed.

There is also a print-and-play paper kit in the latest GitHub release: board, cards, rules, and one sealed envelope you are not allowed to open until the end.

Critical Window is a project of ChipMates gemeinnützige GmbH, a German nonprofit. The code is AGPL-3.0, the content CC BY-SA 4.0, all of it at github.com/chipmates/criticalwindow. The game lives at criticalwindow.org; this page is its door on itch, and the build here is the same build. Seeds are deterministic: share a seed and you share a hidden world.

Sound is off by default and everything works silent. Music by Scott Buckley (CC BY 4.0). The narration is generated with AI voices from the game's own displayed text, disclosed in CREDITS in the repository.