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Tic-tac-toe strategy: how to never lose

Tic-tac-toe is solved: with correct play it’s always a draw. Here is the correct play, plus the traps that beat people who don’t know it.

Play Tic-Tac-Toe nowQuick X and O rounds

The best first move

As X, the strongest practical opening is a corner. The centre is also safe, but a corner gives your opponent more ways to go wrong: if O answers anywhere except the centre, X can force a win.

How to answer as O

  • If X takes a corner, you must take the centre. Any other reply loses against good play.
  • If X takes the centre, take a corner. An edge reply gives X a winning attack.
  • If X takes an edge, the centre or an adjacent corner is safe.

Forks: how games are won

A fork is a move that creates two lines of two at once. Your opponent can block only one, so the other wins. The classic trap: X takes a corner, O takes the centre, X takes the opposite corner. If O now plays a corner, X takes another corner and has a fork. O must play an edge instead, which forces X to block.

The order of priorities

  1. Win if you can.
  2. Block your opponent’s two-in-a-row.
  3. Create a fork.
  4. Block your opponent’s fork (often by forcing them to defend).
  5. Take the centre, then a corner opposite your opponent, then any corner, then an edge.

Test yourself

Follow these rules and you will never lose. Prove it against our unbeatable tic-tac-toe AI, or practise your forks on Easy on the main page.

Play Tic-Tac-Toe nowQuick X and O rounds

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