- Sudoku is played over a 9x9 grid, divided to 3x3 sub grids called "regions"
- Sudoku begins with some of the grid cells already filled with numbers
- The object of Sudoku is to fill the other empty cells with numbers between 1 and 9 (1 number only in each cell) according the following guidelines:
1. Number can appear only once on each row
2. Number can appear only once on each column
3. Number can appear only once on each region
- A summary of these guidelines would be, that a number should appear only once on each row, column and a region… Expand