Tic Tac Toe — the free browser noughts and crosses game you can actually lose

Three squares in a row, on a board of nine. You are X and you always move first; the computer answers as O. That is the whole rule set, and it is the reason a normal tic tac toe game against a computer is worthless as a challenge — played properly by both sides it is a dead draw, every single time.

So this version scores something else: your win streak. Each game you win, the opponent makes fewer mistakes — it starts out throwing away three moves in four and ends up flawless. One loss or one draw ends the run, so the real question is how many wins you can bank before it stops handing them to you. Six is the ceiling. Free, no download, and it plays one-handed on a phone.

How to play

• Tap any empty square to place your X. The computer replies immediately as O.
• Three in a row wins — across, down or diagonally. The winning line lights up.
• Your score is consecutive wins. A loss ends the run, and so does a draw.
• The HUD names the current opponent: careless → casual → sharp → almost perfect → perfect. It reaches perfect on your sixth win.
• On a keyboard, keys 1–9 are the squares in reading order; Space or Enter starts a run.

Tic tac toe is a solved game — so how does anyone ever win?

Tic tac toe was solved long before computers were involved: with perfect play by both sides the result is always a draw. There are 255,168 possible games in total, and every one of them that ends in a win contains a mistake. Nobody has ever beaten a perfect opponent at this game and nobody ever will. That is not a difficulty setting, it is arithmetic — which is exactly why the opponent here begins imperfect and is honest about it in the HUD. Winning is not you outplaying it; it is you punishing a blunder before it stops making them.

Open in a corner. This is the single most useful piece of tic tac toe advice, and it is about how many ways your opponent can go wrong. If you open in the centre, four different replies keep them alive — any of the four corners. If you open in a corner, they have exactly one non-losing answer: the centre. Everything else loses by force. A player who does not know that has a one-in-eight chance of finding the right square by feel, and against this game's early opponents, which pick randomly most of the time, a corner opening is worth far more than the middle.

Then build a fork. A fork — a double threat — is the only thing that actually wins tic tac toe. It means placing one mark that completes two separate lines of two at the same time. Your opponent gets one move before you finish, they can only block one of the two lines, and the other one wins. Every win in the game's 255,168 possibilities comes down to this, either directly or because a single threat went unanswered. The classic version: take a corner, and if they answer anywhere but the centre, take the opposite corner. You now have two diagonally-linked corners and a whole row and column ready to fork on your third move.

The flip side is the defensive half, and it is what ends most runs here. When the opponent has two marks in a line and an empty third square, block it that instant — a threat you ignore for one move is a game you have already lost. And once it reaches perfect, the correct play is simply to draw as fast as possible and accept that the streak is over; the score you banked is the score you got.

More games

If you like an opponent that fights back, try Four in a Row, where it thinks a move deeper every time you win, or Reversi. Or browse all games.