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Mathematics

How breaking the rules of tic-tac-toe makes it way more fun

Noughts and crosses, or tic-tac-toe, is a simple game – but twist the rules and you can really spice it up, says Peter Rowlett

By Peter Rowlett

12 March 2025

WP9M9W hand drawing tic tac toe playing on the sand in summer beach

Two good players will always end noughts and crosses with a draw.

Mikhail Rudenko/Alamy

On the beach, scratching marks in the sand with a stick, my 4-year-old son was already good enough to force a draw in noughts and crosses, also known as tic-tac-toe.

In case there is anyone on the planet unfamiliar with this game, it is played on a 3 × 3 grid, with players taking turns to add their symbol – an X or an O – in one of the spaces. The winner is the first to place three of their symbols in a row horizontally, vertically or diagonally.…

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