Tic Tac Toe

Tic Tac Toe is a free online board game you can play instantly in your browser against a computer opponent named Otto, no download, no account, and no waiting for another player to join. Play on the classic 3x3 grid: tap any open square to place your X, then Otto answers with an O. The first side to line up three marks in a row, column, or diagonal wins; a full grid with no line is a draw. Work through 10 levels that make Otto stronger with every match, from loose random placement early on to flawless blocking and forking near the final grid, where a draw is the best outcome you can force. Win a level to unlock the next opponent strength; Try Again starts a fresh game at the same difficulty.

How to play Tic Tac Toe

1. Choose any empty square on the 3x3 grid to place your X.
2. Otto, the computer opponent, answers with an O after your move unless the game has already ended.
3. Win by lining up three of your marks in a straight line horizontally, vertically, or diagonally.
4. If all 9 squares fill without either side lining up three, the game is a draw and you can replay the level.
5. Clear a level to unlock the next one, where Otto reads the board more carefully and blocks more of your threats.
6. At the highest levels Otto plays flawlessly, so a draw is a strong result — a win only comes if Otto slips up.

Tips

• Take the center square first when it is open — it sits on four different winning lines, more than any edge or corner.
• If you cannot take the center, a corner is the next best opening; corners sit on three winning lines each.
• Always check whether Otto has two in a row with an open third square before making your own move — blocking an immediate loss comes first.
• Watch for a "fork": a move that creates two winning threats at once. Against a high-level Otto, avoid moves that let it fork you, since you can only block one line.

FAQ