Ultimate tic-tac-toe
Nine games of noughts and crosses in a 3 by 3 grid. Win three small boards in a row, but watch out: the square you pick decides which board the computer must play in next.
Also try Four in a Row → Also try Gomoku →
How to play Ultimate tic-tac-toe
How to play
X moves first. Tap or click an empty square in the outlined board; the label above the board names it. The position of your square inside its small board sends the other player to the matching board: play the top-right square and the reply must go in the top-right board.
Winning
Three of your marks in a row wins a small board, and a big X or O covers it. A won board is closed. Win three small boards in a row, across, down or diagonally, to win the game. A small board that fills up without a line is drawn and counts for nobody, and the game is a draw if every board closes without three in a row.
Free moves
If you are sent to a board that is already won or full, you may play in any open board, and every open board gets a dashed outline. Giving the other side a free move is usually a mistake, so think twice before sending them to a closed board.
Opponents
Easy plays loosely and often slips. Medium looks a few moves ahead. Hard searches deeply and punishes moves that hand it a board. You can play X (first) or O (second), or choose Two players to pass one device between friends.
Questions
What happens when you are sent to a board that is already won?
You may play in any open board instead. Here a won board is closed, so nobody can play in it again, and the same goes for a board that is full.
How do drawn small boards count?
A small board that fills up without three in a row counts for nobody, so it blocks every big line through it. If every board is closed without three boards in a row, the game is a draw.
Is going first an advantage in ultimate tic-tac-toe?
Yes, X has the edge, like in ordinary tic-tac-toe. You can choose to play O before your first move if you want a tougher game.
How does the hint work?
The hint runs a deep search like the hard computer’s, rings a square and says why it helps: it wins a board, blocks a line, or sends the other player to a board where it has no line to complete.
Is there a daily game?
No. A game against the computer depends on your own moves, so there is no fixed puzzle to share. Every game is a fresh match.