Sudoku is a Japanese puzzle in which you have to write numbers according to a certain algorithm (so that they do not repeat vertically, horizontally, or diagonally). Simple Sudoku contains 3x3 cells where you have to fill in the missing numbers. Complex Sudokus can contain 6*6, 9*9 or more cells.
In classical Sudoku, the game field consists of 9 blocks of 3x3, in which you must enter the values from 1 to 9. The basic rules of Sudoku are as follows
- Vertical numbers cannot be repeated;
- Horizontal numbers cannot be duplicated;
- A number can only occur once in a 3x3 square.


The rules of classical Sudoku imply that some of the numbers are already fixed at the beginning. This makes it easier to analyze the grid and calculate what values are missing. The number of empty cells and numbers depends on the difficulty of the puzzle. The harder the level, the fewer filled cells (and you will have to use special techniques that will help you fill the whole grid quickly and accurately).
After you fill the whole field with numbers, the puzzle is solved. You can move on to the next one!
Sudoku tips and strategies
There are several solution methods and techniques that will allow you to solve Sudoku quickly and without corrections! The techniques will be useful for beginners and experienced players alike.
If you want to learn how to solve complex levels, we strongly recommend that you study these techniques and start using them when solving Sudoku.