Tic-Tac-Toe (Noughts & Crosses) dates to the Roman Empire, when soldiers scratched quick “three-in-a-row” puzzles in the dust. The tidy 3 × 3 version spread in Victorian England and became the lightning-fast duel we know today.

Just nine squares—but infinite bragging rights. Every move can clinch victory, block defeat, or steer to stalemate. Can you outsmart our AI?