How to Win at Tic Tac Toe (and Why Perfect Play Always Draws)

Tic tac toe has a strange reputation: it is the simplest game most people know, and the one they are most confident they have already mastered. In reality there is a small, complete strategy hiding inside nine squares, and once you know it you will never lose a game again — which is exactly the problem, and exactly the fun.

The uncomfortable truth about perfect play

If both players play correctly, tic tac toe is a draw. Every single time. There is no clever opening that beats a defender who knows what they are doing, and no trap that works against perfect play. The game is solved.

That does not make it a bad game. It makes it a game of mistakes, and mistakes are what you are actually playing against. Your job is not to find a winning move; it is to stay perfect for one move longer than your opponent, and to make the position look complicated enough that they slip.

Opening principles

Take a corner if you can. A corner is the strongest first move because it creates two separate threats at once: a line through the middle of the board and a line along the edge. The centre is strong but predictable; the edge is the weakest opening on the board, because an edge square takes part in only two lines.

If your opponent takes a corner, take the centre. A corner opening is only dangerous if they follow it with the centre. Deny it and the position flattens out.

Never open on an edge. It is the one first move that can lose, because a competent opponent can take the centre and leave you defending for the rest of the game.

Blocking beats building

The single most common mistake in casual play is building your own line while the opponent builds theirs. Tic tac toe is not a race; it is a negotiation. If your opponent has two in a row, block it. Every time. A completed three beats an almost-three, and the player who blocks first usually wins the exchange of threats that follows.

This is why beginners lose: they see their own two-in-a-row and get excited, instead of seeing the opponent’s.

The fork: the only real winning pattern

Since perfect play draws, the way to win is to create a position where two threats exist at once and only one can be blocked. That is a fork.

The classic setup: you have a corner, your opponent has the opposite corner, and you also hold the centre. Placing a mark on the right third board square now threatens two lines at the same time. Your opponent can block one. The other one wins.

Forks are why corners matter. A corner can participate in two lines at once, so a corner plus the centre is the raw material for most winning traps. If you want to practise, set up a board where you hold a corner and the centre, and look for the move that creates two threats at once.

Practising against the computer

Tic Tac Toe on Rovixel has three computer levels, and each one trains a different part of the game:

• Easy plays random squares. Use it to get the corner and centre openings into your fingers.
• Medium always takes a win and always blocks yours, but never plans ahead. It is the right opponent for practising forks: if your double threat works, Medium cannot stop it.
• Hard plays perfectly. It cannot lose, so a draw against it means you made no mistakes either.

How to practise without wasting an evening

Because the game is solved, improvement comes from pattern recognition, not from more games. Learn three positions — the corner opening, the centre response, and the double-threat fork — and you will beat anyone who has not. After that, the only question is how quickly you spot the mistake the other player is about to make.

If you want the rules first and the strategy second, the game itself takes ten seconds to learn: Tic Tac Toe works with taps, clicks or the keyboard, and you can play the computer or a friend on the same device. For more local multiplayer options, see the best two-player browser games to play on one keyboard.