How to Play
The Board
Eleven squares arranged in a 3-3-3 grid with two extra "ear" squares on the far left and far right. Lines connect squares; tokens move only along the lines.
Moving
Each cat may slide forward (rightward) or sideways to an adjacent unoccupied square. Cats may not move backward. Only one cat moves per turn.
The mouse moves in any direction to an adjacent unoccupied square. No jumping for either side.
Winning
- The mouse wins by reaching the leftmost square — the cats’ starting territory.
- The cats win by trapping the mouse so it has no legal move.
- If the cats fail to advance any cat for six consecutive turns, the mouse wins by the Stalling Rule.
A strategy from Winning Ways
Conway, Berlekamp and Guy proposed a surprisingly elegant strategy in Winning Ways. Spoiler-light explanation gated behind sign-in — try the game first, then come back for the analysis.
Stay on the Trace
Conway, Berlekamp and Guy introduced this strategy in Winning Ways. Mark the three light squares +1, the four dark squares -1, the four corners 0. Try to end your turn with the four token-values summing to zero (and not all on zero-squares). The deeper the position, the harder this gets — and the bigger the edge it earns you. The Conway-level AI plays this strategy when it can.