The Sudoku rules

Sudoku is a logic game that is played solo. It consists of completing a grid of 81 cells with numbers from 1 to 9. Be careful! The same number appears only once in a row, once in a column and once in a zone. Sudoku exists in a giant version, but also in a version for children.

The grid

  • The grid of a classic sudoku consists of 81 cells, 9 columns and 9 rows.
  • The grid is then divided into 9 zones.
  • A zone consists of 3 rows and 3 columns.
  • An area, a column and a row contain numbers from 1 to 9.
  • A number does not appear twice in the same area, column and row.

How do you play?

  • At the beginning of the game, the grid is partially filled.
  • Proceed by elimination.
  • Start with a number and see in which row or column it already appears.


Let’s start with the number 1.

It already appears in rows 2 and 3.

It can therefore only appear in row 1.

It already appears in fields 1 and 2.

It can therefore only appear in field 3

  • Look at the rows or columns where only one digit is missing.


The blue column is missing only one number, which is “3”.

If there are several possibilities, you can write the numbers in the corner of the box and eliminate them as you go along.


The last column is missing 2 numbers: 1 and 7.

The red lines mark the boxes where the number 1 cannot appear.

The blue lines mark the cells where the number 7 cannot appear.

By elimination, the number 1 occupies the entire second row.

The number 7 will naturally occupy the last free square and complete the column.


End of the game

  • The game ends when all the squares are completed.


  • There is a 16 square sudoku for children.
  • There is a giant 256-square sudoku for adults.