X & O
The classic Tic-Tac-Toe. Play a friend on one screen, or take on the computer.
Player X Wins!
What is X & O?
X & O is the game many people know as Tic-Tac-Toe, or Noughts and Crosses. Two players take turns marking squares on a 3 by 3 grid. One plays X and the other plays O. The first player to get three of their marks in a straight line wins.
Games like it have been played for a very long time. Similar three-in-a-row games were played in ancient Rome. All you need is a grid and two kinds of mark, so it is easy to start anywhere: on paper, on a beach, or on a screen like this one.
On this page you can play a friend on one screen, or play against the computer. X always goes first. If nobody gets a line before the board is full, the game is a draw.
At a glance
Players: 1 or 2.
Board: 3 × 3, nine squares.
Winning lines: 8 (3 rows, 3 columns, 2 diagonals).
Time: about a minute a game.
Cost: free, no account.
Three simple steps
Pick a mode
Choose Player vs Player to share a screen, or Player vs Computer to play on your own. When you play the computer, you are X and the computer is O.
Take turns
X always goes first. Tap an empty square to place your mark. A square cannot be changed once it is marked.
Get three in a row
A row, column or diagonal wins, and a popup tells you who won. If the board fills up first, it’s a draw. Press Play Again for a new game.
What to do on your turn
Work down this list each turn and play the first thing that fits. It is the simplest way to stop losing.
1. Win if you can
If you have two in a line and the third square is empty, take it and finish the game.
2. Block your opponent
If they have two in a line with the third square empty, take that square before they do.
3. Make a fork
A fork is a move that creates two winning threats at once. Your opponent can only block one, so you win. This is how you beat most players.
4. Take the centre
The middle square sits on four of the eight lines, more than any other square. If it is free, it is usually a strong choice.
5. Use the corners
Corners sit on three lines each. Take the corner opposite your opponent’s, or any empty corner.
6. Edges last
The middle square of each side sits on only two lines. Play there when nothing else is useful.
Openings, and why most games end in a draw
If you are X, start in a corner. After a corner opening, O has only one reply that avoids losing against good play, and that is the centre. Most players do not find it, so a corner start wins a lot of games.
If you are O, answer a corner with the centre. If X starts in the centre, take a corner. Taking an edge square against a centre start loses against good play.
Play well on both sides and it is always a draw. The game has been fully worked out. There are 255,168 different possible games, and when both players make no mistakes, none of them is won by either side. That is why games between experienced players tend to end level, and why the fun comes from spotting a slip.
Beating the computer. In Player vs Computer mode, the computer picks a random empty square on each turn. It does not block and it does not plan, so it can be beaten. Start in a corner, build a fork, and finish the game. It will still win now and then if you leave two squares in a line open.
Ways to play it differently
These are house rules. The game does not track them, so agree on them with your opponent first.
Best of five
Play five games and count the wins. Draws count for nobody. It gives the player who lost the first game a fair chance to come back.
Swap who starts
X goes first and that is a small advantage. In a series, take turns being X so each of you gets the first move equally.
Reverse game
Whoever is forced to make three in a row loses. The popup will still name the player who made the line, so read it the other way round.
Silent game
No talking, no hints and no pointing. It makes the game more serious and a little funnier when someone blunders.
Quick answers
Can I play alone?
Yes. Choose Player vs Computer. The computer picks random squares, so it is a friendly opponent and a good one to practise forks against.
Who goes first?
Player X always starts, in both modes. In Player vs Computer you are X. In Player vs Player, take turns being X if you want to be fair.
Can I choose to be O?
Not yet. X always moves first. In Player vs Player you can agree who plays X in each game.
Is X & O the same as Tic-Tac-Toe?
Yes. Tic-Tac-Toe, Noughts and Crosses and X & O are different names for the same game.
Why do so many games end in a draw?
With no mistakes from either side, the game always ends level. A draw usually means both players blocked well. A win comes from a fork or a missed block.
Can the computer beat me?
Yes, but only by luck. It plays random squares, so it can win if you leave a line open and it happens to pick the right square. Block its two-in-a-row and you are safe.
Does it work on a phone?
Yes. The board resizes to fit your screen, including when you turn your phone sideways. Tap a square to place your mark.
Do I need an account?
No. It is free and runs in your browser, with no downloads or sign-ups. Nothing is saved, and refreshing the page starts a fresh game.
Want more games?
Try Mafia, Housie, Spin the Bottle, Memory Match and more, all free on Relev3n.
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