Tic Tac Toe Strategy: How to Never Lose Again

The truth: perfect play always ends in a tie

Mathematically, Tic Tac Toe has been completely solved. If both players make optimal moves, the game must end in a tie. If you are losing games, it is not bad luck — it is opening or response mistakes. The strategy below covers both.

Going first? Take a corner

The strongest opening move is a corner — not the centre. Why? A corner is part of three winning lines (top row, side column, diagonal). The centre is part of four, but corners force the opponent into more difficult responses. From a corner, the only safe reply for your opponent is the centre.

Going second? Take the centre

If your opponent opened in a corner, take the centre immediately. The centre blocks two of their three winning lines. From here, your goal is just to play defence and force a tie.

• They take a corner → you take the centre.
• They take the centre → you take a corner.
• They take an edge (rare) → you take the centre. They have given you the advantage.

The "fork" — the only way to actually win

A fork is a move that creates two ways to win at once. Your opponent can only block one. The classic fork: you played corner, they played centre, you play the opposite corner. Now you have two corners — both threaten to make three-in-a-row through the empty corner. They can only block one side. Next move, you win.

Defending against the fork

If your opponent is trying to set up a fork (two corners with the centre between them), do not block one of their winning lines — that just speeds them up. Instead, force a counter-threat. Take a corner or edge that creates your own two-in-a-row, so they have to defend instead of attacking. This is the only way to neutralise a fork.

Always-check rule (use this every move)

Before every single move, check two things, in this order:

• Can I win this turn? (Three of my marks in a row with one empty.) Take it.
• Can the opponent win next turn? (Two of theirs in a row with one empty.) Block it.
• Only after both checks, plan your fork or take a strong position.

Mistakes to never make

• Taking an edge as your first move (against a smart opponent, you lose).
• Forgetting to check the "can the opponent win next turn" condition.
• Blocking a fork by joining their winning line instead of countering with your own threat.
• Taking the centre against a corner-opener… actually that is right. Take the centre.

Practice now

Play Tic Tac Toe free in your browser. Test the corner opening against the computer AI. If you follow the always-check rule and learn the fork pattern, you will tie or win every game.