Ultimate tic-tac-toe is the classic game of X and O grown up: nine small tic-tac-toe boards sit inside one big board, and you need three small boards in a row to win. The catch is the send rule. The square you choose in a small board sends your opponent to the matching board on the big grid, so every move is also a decision about where the other player goes next. Play it here for free with a friend on one device, or against the computer on three levels. It works offline once loaded, and a game takes about 10 to 20 minutes.
How to play Ultimate Tic-Tac-Toe
- The big board is a 3×3 grid of small tic-tac-toe boards, 81 squares in all. One player is X, the other O, and X always moves first, anywhere on the board.
- The send rule: the square you play inside a small board sends your opponent to the small board in the same position. Play the top right square of any board, and your opponent must play in the top right board.
- The board you must play in is outlined. If that board is already won or full, you get a free move in any open board.
- Three in a row inside a small board wins it. A big X or O covers the board and nobody can play there again.
- A small board that fills up with no line is a drawn board. It counts for nobody.
- Three won boards in a row on the big grid win the game, across, down or diagonally.
- If no moves are left and nobody has three boards in a row, the game is a draw.
For every rule in detail, diagrams of the send rule and the free move, and the common house rules, read the ultimate tic-tac-toe rules.
Prefer to watch? See the 6-minute video on the Ultimate Tic-Tac-Toe rules page.
Play Ultimate Tic-Tac-Toe on one device
This version is built for two people sharing one screen. Type both names, decide who plays X and start. The bar above the board always shows whose turn it is and which board to play in.
- Aim, then place: 81 squares make small targets on a phone, so on a touch screen your first tap shows a see-through mark where you aimed. Tap the same square again, or press Place, to play it. With a mouse, one click plays. You can switch “Tap twice to place” in the More menu.
- Keyboard play: move with the arrow keys and press Enter or Space to place your mark. Every square has a spoken label, and each move announces where the next player must go.
- Clear board: the board you must play in has a thick outline, the last move carries a small dot, and won boards show one big mark.
- Pass screen (optional): switch it on in the setup or the More menu to show a “Pass to Maya” screen between turns.
- Undo: tapped the wrong square? Undo takes it back. Against the computer it returns you to your own previous turn.
- Rematch and score: Rematch swaps marks, so the player who had O gets X and the first move. A running score is kept for your session.
- Auto-save and offline play: the game is saved after every move, so a refresh or a closed tab doesn’t lose it.
Play against the computer
Choose vs Computer, pick X or O and choose a level:
- Easy plays mostly at random. It always grabs a small board when one is there for the taking, and it won’t hand you the whole game in one move when it can avoid it. A good level for learning the send rule.
- Medium thinks for a moment by playing out many quick practice games from the position and choosing the move that did best. It is a fair test once you know the rules.
- Hard thinks for longer and plays out smarter practice games. It punishes careless sends, so look at where every move takes it before you play.
X moves first, which is an advantage. If the computer feels too strong, take X; if it feels too easy, give it X.
Quick tips
- Look where you are sending. Before you play a square, check the board it points to. If your opponent has two in a row there, find another square.
- Don’t give away free moves. Sending your opponent to a finished board lets them play anywhere, often exactly where they wanted.
- Value the center board. It is part of four lines on the big board, just like the center square in ordinary tic-tac-toe.
Our ultimate tic-tac-toe strategy guide explains these ideas with diagrams. New to X and O? Start with classic Tic-Tac-Toe. For longer lines, try Gomoku or Four in a Row, and our list of pen and paper games has more games for a grid and a pencil.