Noughts & Crosses (Tic Tac Toe) is the classic two-player grid game — play against the computer at Easy or Hard difficulty. Get three in a row to win.
On Hard difficulty, the computer plays a near-perfect game using the minimax algorithm. On Easy, it plays randomly — suitable for children or casual play.
How to play Noughts & Crosses
1
Choose difficulty — Easy or Hard
2
Tap a square — you play first as X
3
The computer responds — immediately as O
4
Get three in a row — horizontally, vertically or diagonally to win
Noughts & Crosses strategy
Noughts and Crosses looks simple, but a few principles separate a casual player from one who never loses. The most important move is to take the centre square whenever you can — it sits on four of the eight possible lines (both diagonals, the middle row and the middle column), so it gives you the most ways to win and the best position to block. After the centre, the corners are the strongest squares and the edges are the weakest.
The key attacking idea is the fork: making two threats at once so your opponent can only block one of them. On defence, always scan for a line where your opponent already has two marks and an empty third, and block it straight away.
Because the game is fully solved, two players who both play perfectly will always draw. The Hard computer uses a minimax algorithm and plays the best move most of the time, but it slips to a random move roughly 15% of the turns — so with sharp, patient play you can punish a mistake and win.
First move
Winning lines it joins
Strength
Centre
4
Strongest
Corner
3
Strong
Edge
2
Weakest
Frequently Asked Questions
Yes, though it's tough. On Hard the computer plays the optimal minimax move about 85% of the time and a random move the other 15%, so it occasionally slips. Punish those mistakes with sharp play and you can win; otherwise expect a draw.
You always go first as X. The computer plays as O.
A game theory algorithm that evaluates all possible moves and chooses the one that minimises the chance of losing. It is the standard approach for perfect Tic Tac Toe play.
With perfect play from both sides, every Tic Tac Toe game ends in a draw. The Hard computer plays nearly perfectly, so a draw is the usual result — but because it slips occasionally, a sharp player can sometimes win.
The centre square. It belongs to four of the eight winning lines, giving you the most chances to make a row and the strongest position to block your opponent.
Yes. With perfect play from both sides it always ends in a draw. The Hard computer plays this near-perfect game but slips about 15% of the time, so it can occasionally be beaten.
A fork is a move that creates two winning threats at the same time. Your opponent can only block one, so you win with the other on your next turn.
It's completely free with no download and no sign-up — just open the page and start playing.
Yes. It runs in any mobile or desktop browser with nothing to install.