Sudoku is a placement puzzle with nine digits and three rules: every row, every column and every 3×3 box holds the digits 1 to 9 exactly once. There’s no arithmetic in it. The digits could just as well be nine colours, and the whole game is working out where each one has to go. New to it? Start with the rules, which walk through a tiny 4×4 puzzle first, or play an easy one right here.
Sudoku
Topics
- Sudoku TechniquesEvery Sudoku technique on PeerPuzzles on its own page, from hidden singles to hidden pairs, each shown on the same real Hard puzzle.
Guides
- Sudoku for Beginners: Start HereNew to Sudoku? Follow this path: the rules on a 4×4 grid, your first Easy puzzle, a six-question warm-up with answers, and when to move up a level.
- Sudoku Rules: How to Play (With Examples)Learn how to play Sudoku: the three rules, a tiny 4×4 puzzle solved step by step, the two moves that start every grid, and an easy puzzle to try.
- How to Solve Sudoku: 6 Techniques That WorkSix Sudoku techniques with diagrams from real puzzles, how far each one gets you at every level, and a Medium puzzle solved from start to finish.
- Sudoku Tips: 10 Tricks to Solve FasterTen Sudoku tips, tested on hundreds of puzzles: which digit to start with, the two-out-of-three scan, notes that take a quarter of the writing, and faster controls.
- 6 Sudoku Mistakes That Break Your PuzzleStuck on a Sudoku, or found a cell with nothing left? These six mistakes cause most broken puzzles. How to spot each one, and how to recover.