noughts and crosses

Noun

 * 1)  A two-player game played on a three-by-three grid, in which players take it in turns to place their respective symbol (either a nought or a cross) in a cell of the grid, the objective being to form a row, column or diagonal of three of one's own symbol.

Synonyms

 * or tic-tac-toe
 * or zeroes and crosses