ticktacktoo

a game in which two players alternately put crosses and circles in one of the compartments of a square grid of nine spaces; the object is to get a row of three crosses or three circles before the opponent does

3×3の9マスの格子に2人のプレイヤーが交互に丸やバツを書き入れ、相手より先に縦・横・斜めのいずれか一列に3つ並べることを目的とするゲーム；三目並べ