How does Sudoku work? - easily explained

Sudoku is known from newspapers, puzzle magazines and increasingly from the Internet. Find out exactly how the Japanese number puzzle works in this home tip.

Solve Sudoku - This is how the logic puzzle works

• The structure of the puzzle is quite simple. A 9 x 9 field grid, from which 81 individual boxes result, must be filled in completely with numbers. The entire square is divided into nine smaller sub-squares.
• The aim is to fill each row, column and sub-square with the numbers from 1 to 9 (see graphic on the right). The order doesn't matter. Under no circumstances may a number appear twice in one of the areas mentioned.
• The challenge is to use a number of digits that have already been entered in the sheet to identify the outstanding. Depending on how many digits are already given, the difficulty is: The more, the easier the Sudoku puzzle.

Sudoku - different variations

• There are now all kinds of modifications to the original Sudoku game. For example, there is the X-Sudoku, in which, in addition to sub-squares, rows and columns, the 2 main diagonals must be filled with the correct number of digits from 1 to 9.
• The so-called multi-sudoku is very popular. Not one, but five meshes that mesh with each other must be filled in. They are connected at the 4 corners of the middle grid. This variant is very often printed in puzzle magazines.
• The killer sudoku is also very demanding. Areas are marked with a certain number in the grid. All digits in that area must add up to exactly this number.
• The Nonomino Sudoku is a no less complicated version. The 9 sub-squares are changed to bulky clusters. These must also be numbered 1 to 9.

Play Sudoku: Click here for the free online game

In the next article, we will teach you the right tactics to crack a sudoku.