How to Play Chomp
Chomp was described by David Gale in 1974 and named by Martin Gardner. It is a game of pure structure: a staircase of chocolate and one bad square.
The rules
- A rectangular bar of squares. The top-left square is poisoned.
- On your turn pick any remaining square and eat it along with every square below it and to its right. The bar always keeps a staircase shape.
- The player left with only the poisoned square must eat it and loses.
Playing on kawu
Tap a square to bite. Choose a 4×5, 5×7 or 6×9 bar, play first or second against the computer (three levels, hard is perfect), or two players on one device. Hint shows a winning bite when there is one.
Next, read the Chomp strategy.
Frequently asked questions
Can I eat the poisoned square to end a game I'm losing?
Only when it's the last square left: then you have no choice, and you lose. While other squares remain the poison can't be chosen.
Who wins Chomp?
On any rectangular bar the first player has a winning strategy, proved by a strategy-stealing argument that doesn't say what the strategy is. The computer finds it by searching; people have to feel their way.
Last updated 2026-10-21