Order and Chaos

Order and Chaos is a variant of tic-tac-toe played on a 6 by 6 board. Stephen Sniderman invented it and introduced it in Games magazine in 1981. The two players have different goals: the player called Order tries to make five like marks in a row, either Xs or Os, while the opponent called Chaos tries to stop that from happening. Unusually, both players place both Xs and Os, Order moves first, and pieces are never moved once placed, so the game can be played with pencil and paper. The original rules implied that six in a row also wins, and that version was weakly solved as a forced win for Order. Sniderman later suggested that six in a row should not count, and that version is weakly solved as a forced win for Chaos, who can use a pairing strategy.