Sudoku Rules

How to play every variant we offer, one grid at a time — from the standard 9x9 board to diagonals, cages, irregular regions, and giant 21x21 grids.

The complete rules of 9x9 Sudoku explained with board diagrams, a worked example, and difficulty levels.

The standard 9x9 rules plus two diagonal lines, explained with a worked example and difficulty levels.

Standard Sudoku rules plus dashed cages that must sum to a target, explained with worked examples.

The standard 9x9 rules with irregular regions instead of 3x3 boxes, explained with a worked example.

Five overlapping 9x9 grids on a 21x21 board, and how the four shared boxes link them together.

Every rule of 6x6 Mini Sudoku explained with board diagrams, a worked example, and answers to common beginner questions.