A mathematical game for two players. The game starts with one or more lines of pins, and the players take turns removing either one pin or two adjacent pins from any line. (This represents knocking them down with a bowling ball.) The winner is the player who removes the last pin.

If the game is played with a single line of pins, the first player wins by a symmetry strategy. They begin by removing the central one or two pins, leaving two lines of equal length. Then whatever their opponent does to one line, they do the same to the other line of the same length.