How to Play Tic-Tac-Toe

New to Tic-Tac-Toe? Here are the complete rules, how a turn works, and how the game is won — with examples you can follow.

Tic-Tac-Toe (also called noughts and crosses) is a two-player game on a 3×3 grid. One player is X, the other is O. You take turns, and the first to line up three of your marks in a row wins. A full game takes about a minute — which is exactly why it's a perfect "send a link and play a friend" game.

What you need

The rules

  1. X moves first, placing an X in any empty square.
  2. Players then alternate turns, each placing their mark in any empty square.
  3. You cannot move into a square that's already taken.
  4. The first player to get three of their marks in a straight line wins — horizontal, vertical, or diagonal.
  5. If all nine squares fill up and no one has three in a row, it's a draw (a "cat's game").

How you win

A win is any three-in-a-row of the same mark. There are eight winning lines — three rows, three columns, and two diagonals:

The moment either player completes one of those lines, the game ends immediately.

A worked example

The key winning idea is a fork — making two threats at once so your opponent can't block both. Here's how it plays out.

1. X takes the center. The strongest opening square — it sits on four of the eight winning lines.

2. O replies in a corner to stay flexible.

3. X takes the opposite corner. Now X threatens two lines at once — the main diagonal and the bottom row. That's the fork.

4. O can only block one threat. Whatever O plays, X completes the other line next turn — X wins.

💡 Good to know: with perfect play from both sides, Tic-Tac-Toe is always a draw — you only win when your opponent slips up. So the real game is not making the first mistake. Taking the center first is the safest opening; if your opponent opens in the center, reply in a corner, not an edge.

Ready to play? Play Tic-Tac-Toe online → — send a friend the link and you're in a match in seconds. Then sharpen up with How to Win at Tic-Tac-Toe.