Beginner rules
Sudoku Rules
Learn the row, column, and 3x3 box rules that every Sudoku puzzle follows.
What it means
A valid Sudoku solution uses every number from 1 to 9 exactly once in each row, column, and 3x3 box. Start by reading given numbers, then look for empty cells where the rules leave only one legal option.
How to use it
- Scan each row for missing numbers.
- Check the matching column before placing anything.
- Confirm the 3x3 box still allows that number.