Take turns tapping an empty square. One of you is ✕, the other ◯.
Get three in a row — across, down or slanting — and you win.
Fill the board with nobody in a row and it is a tie. That happens a lot once you are both good at it.
vs Robot: Easy misses things on purpose, Tricky plays properly most of the time, and Genius never loses — a tie against it is a win.
The score at the top keeps count until you reset it with ↺.