❌ Tic-Tac-Toe

How to play

Players take the nine squares of a three by three grid in turn, X first, and the first to hold three in a line wins. There are eight lines: three rows, three columns and the two diagonals. If all nine squares fill with no line, the round is a draw. You can play against another person at the same screen or against the computer, which always plays O and replies about a third of a second after your move.

• Click an empty square — places your mark there. Squares already taken are ignored.
• 2 Players button — switches to two people sharing the screen and starts a fresh round.
• vs AI button — switches to playing the computer and starts a fresh round.
• New Round button — clears the grid without touching the running totals.

Scoring

The three counters at the top track completed rounds rather than points: wins for X, draws, and wins for O. They increase by one whenever a round ends and are not reset by the New Round button, so the tally accumulates for as long as you keep playing. Switching between two-player and AI mode also starts a new round without clearing the totals, which means the two modes share a scoreboard.

Tips

• The centre square sits on four of the eight winning lines, more than any other, and is the strongest opening move.
• Corners are next best. Each belongs to three lines, while an edge square belongs to only two.
• Look for a move that completes two lines at once. Your opponent can only block one of them.
• The computer opponent searches every remaining position, so it cannot be beaten. Against it a draw is a win.

Frequently asked questions