Game rules

To complete a Sudoku grid you must fill all the empty squares with numbers from 1 to 9 while respecting the following 3 rules:

The complete grid of 9 rows by 9 columns is made up of 9 small squares of 3 rows by 3 columns. It is only these small squares that must respect the single number rule. No other squares have any constraints.

Only rows, columns and small squares must respect the single number rule. This rule does not apply to diagonals. Therefore, there can be several times the same number in the same diagonal.

Sudoku puzzles are designed so that there is only one final solution (all puzzles published on this site are checked and strictly follow this rule). If a puzzle has multiple possible solutions, they are of poor quality.