Sudoku
Classic 9x9 number placement puzzle.
How to Play
Fill every empty cell with a digit from 1 to 9 so that each row, each column, and each 3x3 box contains every digit exactly once. Pre-filled cells (shown in bold) cannot be changed. Conflicting cells are highlighted in red.
Controls
| Key | Action |
|---|---|
| Arrow keys / WASD / hjkl | Move cursor |
| Mouse left-click | Focus a cell |
1-9 |
Fill cell with digit |
Backspace |
Clear cell |
Ctrl+R |
Reset puzzle |
Ctrl+H |
Toggle full help |
Escape |
Return to main menu |
Modes
| Mode | Clues | Description |
|---|---|---|
| Beginner | 45 | Single Candidate / Scanning |
| Easy | 38 | Naked Singles |
| Medium | 32 | Hidden Pairs / Pointing |
| Hard | 27 | Box-Line Reduction / Triples |
| Expert | 22 | X-Wing / Y-Wing |
| Diabolical | 17 | Swordfish / XY-Chains |
Elo Difficulty
Named modes are compatibility presets. Use --difficulty <0..3000> to target a
specific Elo difficulty for generated puzzles.
Quick Start
puzzletea new sudoku beginner
puzzletea new sudoku medium
puzzletea new sudoku diabolical