Counterexample Hunter
Build the number that refutes the claim.
4
levels2–8 min
a run, player-paced6
samplesNo timer
player-paced, always
Counterexample Hunter
Build the number that refutes the claim.
Each level states a plausible universal claim. You get a handful of candidates; the bench checks each one exactly. One counterexample kills a claim forever. Some claims cannot be killed — for those, the win is saying why.
Levels
4 levelsThe tag on each level says how it gets harder. Levels gate on ideas, not on each other — jump wherever it gets interesting.
What decides the outcome
The game never restates the science — it imports it. These are the model layers that do the deciding.
Exact primality (isPrime over bigint). The claims compose imported predicates; nothing here computes number theory of its own.
Why it teaches
The author's own delete-the-science argument: remove this game's substrate and there is nothing left to choose.
The win condition is the logic itself: a candidate refutes only when it satisfies the hypothesis and breaks the conclusion, and the bench's feedback on a failed candidate — which half held — is the distinction between P, Q and P-implies-Q. On a true claim the budget runs dry and the learner must select the reason no candidate can work, which is where refutation turns into proof.
Accessibility
The contract's declarations, stated before you commit to a run.
Keyboard
Playable start to finish from the keyboard.
Screen reader
Every move is narrated — the narration is the state, not a description of a picture.
Motion
Reduced-motion: consequences render statically.
Audio
Silent — no sound, and nothing on screen moves on its own.