Play Chomp Online Free | Poisoned Chocolate Bar Game vs AI

Chomp on Arcadia

Chomp is the chocolate bar you must NOT finish. Invented by mathematician David Gale in 1974 and made famous by Martin Gardner's Scientific American column, it hides one of the most elegant results in game theory behind a two-minute game: the first player provably always has a winning strategy, yet mathematics cannot say what it is in general.

Arcadia's bar is 4x7, and on Glutton difficulty the AI has that bar completely solved: one wrong bite and the poison is yours. You always bite first, so a perfect line to victory always exists.

How to Play

The bar is a 4x7 grid of chocolate squares; the top-left square is poisoned.
On your turn, click any square: you eat it plus every square below and to its right.
Bites alternate; eaten chocolate never returns.
You may never bite the poison while other chocolate remains.
The player left with ONLY the poison square must eat it — and loses.

Core Rules

A bite at square (row, column) removes that square and the whole rectangle below-right of it.
Any remaining square is a legal bite except the poison.
No passing: you must bite every turn.
The loser is whoever eats the poisoned top-left square.

Strategy: Think in Staircases

After any sequence of bites the bar is a staircase: rows never get longer as you go down. Learn to read positions as staircases, not squares.
The square 2x2 block (with poison in the corner) is lost for the player to move: every reply hands back a winning bite. Aim to hand exactly that shape to the AI.
On a 2-row bar the rule is known: keep the top row exactly one longer than the bottom row. Steer endgames into 2-row shapes you understand.
The L-shape with one long arm is usually a trap for whoever must move; count carefully before creating one.
Big greedy bites feel strong but usually gift the tempo; small corrective nibbles control the staircase.

Practical Tips

Hover a square to preview exactly what your bite would remove.
The red glow shows the Glutton's bite before it lands.
Start against Sweet Tooth to learn shapes, then graduate to the Glutton.
Remember: from the opening position you are never lost. If the Glutton beats you, the mistake was somewhere in YOUR line.

Chomp rules, history & strategy guide

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FAQ

What is the trick to winning Chomp?

There is no known general formula — that is the famous part. But small boards are fully solvable: learn the lost shapes (like the 2x2 block) and the 2-row rule (top row one longer than bottom), and steer the staircase toward them.

Why does the first player always win at Chomp?

By the strategy-stealing argument: if the second player had a winning answer to a corner nibble, the first player could have reached that same position by playing it directly. The proof shows a winning strategy exists without revealing it.

Can I ever bite the poisoned square?

Only when it is the last square left — and then you must, which loses the game. While any other chocolate remains, the poison is off-limits.

Is the Glutton truly unbeatable?

No — you move first, and the first player always has a winning line. The Glutton plays the 4x7 bar perfectly, so a single inaccurate bite loses, but a perfect line beats it every time.