Two players alternately place pieces (typically X's for the first player and O's for the second) on a 3 × 3 board. The first player to get three matching symbols in a row (vertically, horizontally, or diagonally) is the winner. If all squares are occupied but neither player has three symbols in a row, the game is a tie.

naughts and crosses | three-in-a-row | ticktacktoe | wick wack woe

≈ 100 BC (≈ 2125 years ago)

fair | finite | futile | perfect information | sequential | two-player | zero-sum