The game is played on a 3×3 grid of smaller tic-tac-toe boards. You have to win three small boards in a row to win the game.
The cell you play on the small board determines which board your opponent must play in next on the big board. The highlighted board shows where the next player must go.
Get three in a row on a small board and it becomes yours.
Claim three boards in a row on the big grid and you win the game.