Overview
Learn the classic 3×3 game of Xs and Os, including winning lines and simple strategy.
Objective
Be the first player to place three of your symbols in a horizontal, vertical or diagonal line.
What You Need
Paper and pencil, or a 3×3 board
Setup
Draw a 3×3 grid. One player uses X and the other uses O. Decide who goes first.
How to Play
Players alternate placing one symbol in any empty square. Once placed, a symbol does not move.
Key Rules
After each turn, check all rows, columns and diagonals. If every square is filled without a winning line, the game is a draw.
Useful Terms
- Line: Three matching symbols across a row, column or diagonal.
- Block: Occupy the square an opponent needs to complete a line.
- Fork: Create two different winning threats at once.
Rules in More Detail
Because the board is only 3×3, every move matters. After the opening move, always check in this order: can you win now, can your opponent win next turn, can you create a fork, and can your opponent create a fork?
Winning the Game
The first player to make a straight line of three matching symbols wins.
Worked Example
If you have X in the top-left and centre squares, placing X in the bottom-right completes a diagonal line and wins.
Strategy Tips
- The centre is a strong opening square.
- If your opponent has two in a row, block the third square.
- Look for forks that create two winning threats at once.
- Corner squares are generally more useful than edge squares.
Beginner Notes
With perfect play from both sides, the standard 3×3 game ends in a draw. The fun for beginners is learning to recognise threats and forks reliably.
Common Mistakes
- Placing a symbol in an occupied square.
- Missing a diagonal winning line.
- Continuing play after three in a row has already been made.
Variations & House Rules
Try larger grids with longer winning lines, or play several rounds and award one point for each win.
Frequently Asked Questions
Does a diagonal count?
Yes.
What if all nine squares are full?
If nobody has three in a row, it is a draw.
Can a symbol move after it is placed?
No, not in the standard game.
Score Card
Open the CS17 fillable Noughts and Crosses Game Sheet to enter player names and game results on screen, then print it or save it as a PDF.