Tsuidoku

You thought you knew sudoku? A 4th rule changes everything: every color runs 1-9, 81 unique pairs. Plus a new worldwide daily grid.

Sudoku was the training. Tsuidoku is the real game.

Tsuidoku is a logic puzzle for players who have outgrown ordinary Sudoku. It keeps the classic 9×9 grid and adds a fourth constraint that changes everything, turning a familiar pastime into a genuinely new challenge.

THE 4 RULES Every row, column and 3×3 region must contain the numbers 1-9 AND all 9 colors. That is the classic part. The twist: each color must also contain all 9 digits. The result is 81 unique number-and-color pairs. Place a "Red 5" once, and it can never appear anywhere else on the board.

This single rule unlocks deduction techniques you will not find in any other puzzle.

TWO WAYS TO PLAY

• Practice: solve at your own pace. No timer, no pressure, hints whenever you want. Perfect for learning the techniques.
• Ranked: the real challenge. Win, build streaks, and climb a worldwide ranking that reflects your true skill. Every game counts.

PROVE YOUR SKILL Tsuidoku ranks every player on a single worldwide ladder based on real skill, not luck and not how much free time you have. The better you play, the higher you climb. Reach the top and show the world you have truly mastered the puzzle.

SIX DIFFICULTIES Easy, Medium, Hard, Expert, Master and Diabolic, so there is a grid for you whether you are learning the ropes or chasing a flawless run.

MASTER THE TECHNIQUES

• Rainbow Technique: follow a number through its nine colors to find where it belongs.
• Chromatic Circle: follow a color through its nine numbers to reveal the missing digit. Tap a cell to cycle through highlight modes and watch the logic light up.

COMPETE AND CONNECT

• Add friends, search for players and compare your stats.
• Chat with friends and other players right inside the app.
• A detailed profile tracks your records across every difficulty.

BUILT RIGHT

• Play offline; your guest scores are saved on your device.
• Available in 27 languages.
• Fair play guaranteed: every ranked score is verified server-side.

Think you have mastered Sudoku? Tsuidoku is where the real game begins. Download now and create your first 81 perfect pairs.