How to Play Sudoku
Sudoku is a number puzzle with only three rules. Learn them here, then move on to the techniques that help you solve any puzzle.
The Rules
The grid is 9 cells wide and 9 cells tall, split into nine 3×3 boxes called houses. Each cell holds one number from 1 to 9.
Step through
Sudoku in Six Steps
Welcome to Sudoku
Sudoku is a number puzzle with only 3 rules.
Row Rule
Every number must appear only once in each row.
Column Rule
Every number must appear only once in each column.
House Rule
Every number must appear only once in each house.
A house is one of the nine 3×3 boxes in the grid.
Given Numbers
Every puzzle starts with some numbers provided. These are called givens, and they can't be changed.
Complete the Grid
Your goal is to complete the grid without breaking the three rules.
Rules at a Glance
Rows
Each of the 9 rows contains 1 to 9 exactly once.
Columns
Each of the 9 columns contains 1 to 9 exactly once.
Houses
Each of the 9 houses (3×3 boxes) contains 1 to 9 exactly once.
That's it. There's no maths involved. The numbers could just as easily be letters or colours; what matters is that each one appears once per row, column, and house.
Your First Puzzle
Getting started
- Start with rows, columns, or houses that are already nearly full
- For each empty cell, ask which numbers are still possible
- When only one number fits, place it and look again
Good habits
- Don't guess: every number can be found with logic
- Use pencil marks to note the candidates for a cell
- If you get stuck, move to a different part of the grid
Ready to Try?
Magic Sudoku walks you through these rules the first time you open it, and its hints explain the next step whenever you get stuck.