The goal
Get three of your marks in a row before your opponent does: across, down or diagonally.
The board and the marks
The board has 9 squares in 3 rows and 3 columns. One player is X and the other is O. Once a mark is placed, it stays on that square until the game ends.
Against the computer, you always play X. In an invite game, whoever creates the room plays X and whoever joins through the link plays O.
Who goes first
In the first game, X goes first. After that, players take turns going first: one player starts one game, and the other starts the next. This applies against the computer and in invite games, rematches included.
How to play
- On your turn, place one of your marks on an empty square.
- You can't play on a square that's already taken, and you can't skip your turn.
- Players take turns, one mark each, until someone gets three in a row or the board is full.
How to win
You win by filling one of the eight lines on the board with three of your marks: the three rows, the three columns or the two diagonals. The game ends right then.
With only 9 squares, the player who goes first places at most 5 marks, and the other at most 4.
Cat's game
If all nine squares are filled and no one has three in a row, the game is a tie, known as a cat's game.
If neither player makes a mistake, every game ends in a cat's game. To win, you have to take advantage of your opponent's slipup.
Against the computer
You pick your opponent from the Backyard Town gang. After each game, PLAY AGAIN keeps your streak going and STOP shows your tally of wins, cat's games and losses.
- Scribble (easy)
- Plays for fun more than strategy: finishes a row only once in a while and doesn't block yours.
- Nino (medium)
- Almost always finishes his rows and blocks yours, but he can't see a double threat coming.
- Granny Quelonia (hard)
- Plays perfectly and never loses: the best you can get from her is a cat's game.
Playing someone by invite
- Invite
- Choose to play with someone, pick your character, enter your name and send the link. Whoever opens it picks one of the characters left and joins as O.
- Play at your own pace
- The game is saved on the site: each of you plays your turn whenever you can, and the game lets you know when the other player moved.
- Rematch
- When the game ends, you both decide whether to play again in the same room, and the other player goes first.
- Resigning
- If you resign, you lose and the win goes to the other player. The game asks you to confirm first.
- No-shows
- If the other player hasn't moved in over 2 days and it's their turn, you can end the game as the winner. A room with no moves for 7 days closes on its own.
- Watching
- Anyone who opens the link to a room that already has two players can watch, up to 50 people per game.
Tips for beginners
- The center square is part of four lines, and each corner is part of three. That's why opening in the center or a corner usually beats opening on an edge.
- If you have two in a line with the third square open, take it and win: going for the win comes before blocking.
- Before every move, check whether your opponent has two in a line with the third square open. If so, block it.
- Look for a double threat: one move that sets up two lines at once. Your opponent can only block one of them.
Variations of tic-tac-toe
In many families, the loser goes first in the next game; on Selminha.com, players simply take turns going first. There are also versions on bigger boards, where you need four or five in a row, and versions where each player has only three pieces and, once they're all down, moves them around. Here you play classic tic-tac-toe on a 3-by-3 board.