Controls

You play by taking bites. Tap any remaining square, and it disappears along with every square above and to the right of it. You must take a bite on your turn.

The one rule to remember is which square is deadly:

• Biting removes the square you pick and all squares above and to the right of it, so a bite in the lower left clears a large chunk, while a bite in the upper right removes only a little.
• The poison square is the bottom-left one. It can never be safely eaten, and the player forced to take it loses, so the whole game is about not being the one left with only that square.

You must take a bite each turn, so you can never pass to avoid the poison.

The first player is known to have a winning strategy, though it's unknown for large boards. Against the computer, the difficulty rises across eight levels.

Tips

• Never eat the poison square willingly. The bottom-left square loses the game, so your entire goal is to force your opponent to be the one with no choice but to take it.
• Think about what your bite leaves behind. Each bite removes a whole region, so picture the shape of the bar after your move and whether it hands your opponent a safe reply or a losing one.
• On small boards, reason it out. With few squares, you can often work out the winning move by thinking a few steps ahead, so take a moment to plan rather than biting randomly.
• Try to mirror on square boards. On a square bar, a known first-player idea is to bite to leave an L-shape and then mirror your opponent's moves, which can keep you in control.
• Avoid leaving a single safe row or column. Positions that leave a simple line of squares are often easy for your opponent to navigate to a win, so watch for those before you commit to a bite.
• Watch the shrinking board closely. As the bar gets smaller, the losing traps become clearer, so pay extra attention near the end when a single wrong bite can force you onto the poison.

Frequently asked questions