How to Play Tic Tac Toe Online (Rules, Strategy and How Not to Lose)

Tic Tac Toe takes about a minute, needs no equipment and works for almost any age, which is why it's still the first game most people learn. Playing it online means you can have a game with someone anywhere, or with the computer when nobody else is around. Here's how it works and how to stop losing.

The rules

• Two players, one grid. The grid has three rows and three columns. One player is X and the other is O.
• Take turns. On your turn you claim one empty square. You can't move or remove a mark once it's placed.
• Three in a row wins. Across, down or diagonally all count.
• A full grid is a draw. If all nine squares are used and nobody has a line, nobody wins.
• The starting player swaps. X goes first in the first game, and the opener changes on every rematch so it stays fair.

How to win more often

Played perfectly by both sides, Tic Tac Toe is always a draw. So winning comes from the other player making a mistake, and your job is to set up positions where a mistake is easy to make.

• Open in a corner. There are more ways for the second player to go wrong against a corner than against the centre. If they don't reply in the centre, you can usually force a win.
• Build a fork. A fork is two lines that each need one more mark. Your opponent can only block one of them, so you win with the other.
• Block first, build second. If your opponent has two in a row, close it before doing anything else.
• Look one move ahead. Before you place a mark, check where your opponent's best reply would be. If it gives them a fork, pick a different square.

If you're playing O

• X opened in a corner: take the centre. Any other reply loses against good play.
• X opened in the centre: take a corner. An edge square loses.
• X opened on an edge: take the centre or a corner next to it, and watch for a fork.

Playing the computer

The computer opponent plays almost perfectly, but it misses a move now and then. Don't expect it to fall for an obvious trap. Instead, keep making safe moves and wait for it to slip, then take the fork. If you can draw it every time, you've learned the game.

How to set it up

Create a room, send the four-digit code or the link to a friend, and you're playing. To play the computer, add a computer player from the lobby before you start. Anyone else who joins the room watches, and takes a seat if one of you leaves. If you want something longer, Connect 4 works the same way on a bigger board.