Infinite Tic-Tac-Toe: Rules and Strategy (No Draws)

Infinite tic-tac-toe is played on the normal 3×3 grid with one twist: each player can only have 3 marks on the board. When you place your 4th mark, your oldest mark disappears. The board never fills up, so there are no draws: someone always wins in the end.

Rules

X goes first, then players take turns placing a mark in an empty square.
Once you have 3 marks, placing a new one removes your oldest mark (the first of your three that you placed).
The first player to have three in a row (across, down or diagonally) wins.
You can't place a mark on a square that's taken, including your own mark that is about to vanish.
On Royal Duels a game that reaches 60 moves without a winner is called a draw. It almost never happens.

How to read the board

The mark that will vanish next is shown faded. When it's your turn and you already have 3 marks, your oldest one pulses: it will disappear the moment you play.

Strategy

Count the clock. Before you go for two in a row, check which of those marks is your oldest. A line that relies on a mark about to vanish is a trap for you, not your opponent.
Blocking is temporary. A block made with your oldest mark disappears next turn, and the threat comes back. Block with marks that will stay.
Win on the vanish. The square your opponent's oldest mark is on opens up when they move. Plan a line that uses that square.
The center still matters, but because marks rotate out, controlling it for long is hard. Timing beats position.

Play it now

Play against the bot (easy, medium or hard) or send a link to a friend. Wins earn 🪙 points toward the monthly prize. You and the bot take turns going first.

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