OXO is played on a board consisting of 3x3 squares. Initially all squares are empty. The goal of OXO is to be the first to form a row with 3 own marks.
Taking turns, the players put their mark (a cross or a circle) in one of the empty squares.
The first player to form a row (horizontally, vertically or diagonally) with 3 of his own marks wins the game.