Tic-tac-toe
X and O. Three in a row wins.
The game everyone knows, also called noughts and crosses or X and O, on a glowing neon board. Play the computer on three levels, play a friend on the same screen, try the five by five big board where you need four in a row, or work through 60 puzzles. It has music of its own, and it remembers your record against each level.
Free. No download, no sign-up. Works in the browser on phones, tablets and computers.
How to Play
The board is three squares by three. Two players take turns putting their mark in an empty square: one plays X, the other O. The first to get three of their marks in a row - across, down or corner to corner - wins the round. If the board fills up and nobody has a row, the round is a draw.
Against the computer you always play X. Who moves first swaps every round, so you start one round and the computer starts the next. Your score for the sitting is at the top: your wins, the draws, and the computer's wins.
| Action | Phone or tablet | Keyboard |
|---|---|---|
| Put your mark | Tap a square | 1 to 9 (the top row is 1 2 3), or the arrows and Enter |
| New round | The New round button | N |
| Back to the menu | The Menu button | Esc |
Ways to Play
- Against the computer, Easy. It takes a win when it sees one, and otherwise plays anywhere. A good place to learn.
- Against the computer, Medium. It always takes a win and always blocks yours, and plays well most of the time. Beat it with a fork: a move that makes two threats at once.
- Against the computer, Hard. It never loses a classic game. A draw against Hard is a good result.
- Two players. Take turns on the same phone or computer.
- Big board. Five squares by five, and you need four in a row. It takes longer to plan and can be won against every level of the computer.
- Puzzles. Sixty positions where X can force a win, against the best defence. Find the winning moves.
- Match. Turn on first to 3 in Settings: the first to win three rounds takes the match and a trophy.
In Settings you can also turn the music on or off and change the marks: classic X and O, hearts and stars, cats and dogs, or strawberries and lemons.
How to Never Lose
Tic-tac-toe is a solved game: if both players make no mistakes, every game ends in a draw. That is why the Hard computer never loses. You can play the same way:
- Win first, block second. On every move, look for a square that gives you three in a row. If there is none, look for a square where your opponent would make three, and take it.
- Going first, start in a corner or the centre. A corner sets the most traps: unless your opponent answers in the centre, you can force a win.
- Going second, answer a corner with the centre, and answer the centre with a corner. Answering the centre with an edge square loses against good play.
- Make forks. A fork is a move that creates two rows that each need one more mark. Your opponent can block only one, so you win with the other.
- Stop forks. If you hold the centre and your opponent holds two opposite corners, play an edge square, not a corner. The edge forces them to block you and the fork never comes.
Big Board Tips
On the five by five board you need four in a row, across, down or diagonally. There are 28 possible rows of four, and most of them run through the middle squares.
- Take the middle early. The centre square is part of more rows than any other.
- An open three wins. Three in a line with an empty square at both ends of a five-square line can be finished either way, and your opponent can only block one end.
- So block a two before it grows. When your opponent has two together with space on both sides, put a mark at one end now.
- Watch the diagonals. They are the rows players most often miss, on both sides of the board.
The computer on Easy blocks most of the time and plays near its own marks. Medium blocks every loss and looks two moves ahead. Hard looks four or five moves ahead and spoils most double threats, but it can be beaten.
Puzzles
Each puzzle is a game already under way, with X to move. Puzzles 1 to 20 are wins in one move, 21 to 45 wins in two, and 46 to 60 wins in three, and the computer defends as well as it can. Solve a puzzle on the first try for three stars, on the second for two, and after that for one. Each one you solve opens the next.
Questions
- Is tic-tac-toe always a draw? With perfect play from both players, yes. Games are won when someone makes a mistake, most often by missing a fork.
- What is the best first move? A corner or the centre. Both lead to a draw against perfect play, but a corner gives your opponent more ways to go wrong.
- Can I beat the Hard computer? Not on the classic board, but you can always hold it to a draw. On the big board, yes.
- Is my score saved? Your record against each level and your puzzle stars are kept in your browser on this device. The score at the top starts again each time you choose a game.
Screenshots
Choose how to play Three in a row