A logic game between two opponents on a square field of 3 by 3 cells or larger. One of the players plays with "crosses", the second - with "noes". Players take turns putting 3×3 signs on the free cells of the field (one is always crosses, the other is always zeros). The first one to line up 3 of his pieces vertically, horizontally or on a large diagonal wins. If the players filled in all 9 cells and it turned out that there are no three identical signs in any vertical, horizontal or large diagonal, the game is considered to end in a draw. The first move is made by the player placing crosses. Usually, at the end of the game, the winning side crosses out with a line its three characters (zero or cross), which make up a continuous row.