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Why Play on Stone Online?
Free to Play
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No Signup Needed
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Real-time Multiplayer
Play with real opponents from around the world
Practice with AI
Sharpen your skills against AI at 4 difficulty levels
Play vs AI
Choose your difficulty level and start playing instantly
About this Game
Play sudoku multiplayer online — the classic number puzzle, now a head-to-head battle. Sudoku Duel puts two players on the same board, racing to fill cells correctly. One wrong move costs you points, so speed without accuracy is a losing strategy. Way more intense than solving solo.
On Stone Online, you jump right in — free, instant, browser-based. Sharpen your skills against AI bots at four difficulty levels, then challenge real players worldwide. No download, no signup, no waiting.
Sudoku traces back to Leonhard Euler's Latin squares from the 18th century and exploded in popularity in Japan in 1986. Sudoku Duel adds competitive multiplayer to this beloved puzzle, creating an entirely new experience.
How to Play
You play on a standard 9x9 board split into nine 3x3 blocks. Some cells come pre-filled. Each row, column, and block must hold the numbers 1 through 9 with no repeats.
Take turns placing numbers in empty cells. A correct number earns you points. A wrong number costs you a penalty.
The game ends when the puzzle is complete. Whoever has more points wins. Speed and accuracy decide everything.
Game Modes
Frequently Asked Questions
How do I play Sudoku Duel online?
Click Play Now, create a room or join an existing one. Once all players are ready, the game starts automatically.
Is Sudoku Duel free to play?
Yes, Sudoku Duel on Stone Online is completely free. No downloads, no ads, no subscriptions.
How many players can play Sudoku Duel?
Sudoku Duel supports 2 to 2 players on Stone Online.
Do I need an account to play?
You can play instantly with anonymous login. No email or registration required.
No Signup Needed
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