Hotseat by default — click a piece, then a highlighted square, for both sides. Stepping back through the move list pauses the engine; jump to the latest position to resume.

Every piece moves one square in any direction, like a king. Rock takes Scissors, Paper takes Rock, Scissors takes Paper — nothing else can be captured. White wins by reaching file i, Black by reaching file a (the tinted edges). Running out of legal moves loses. Three repetitions of the same position is a draw.