|The Columns :
Looking at the illustration below, as with rows, another tip to a rule of Sudoku is that there are also nine columns in the traditional version of the game. Again, each column must have the numbers 1 through 9 without duplication anywhere in the column.
|The Regions :
The last main tip to know is the Sudoku rule stating that a region is set up as a 3x3 grid, and like columns and rows, must contain the numbers 1 through 9 without repeating any number. Here is an illustration of a region.
|Another tip and rule of Sudoku is that no two regions will be the same. This means that once a region is completed, that number combination will not be used again anywhere in the puzzle.
The simplest tip to remember about rules of Sudoku is that you complete the puzzle having every column, region and row containing the numbers 1 through 9 only one time each.
An added tip to remember Sudoku rules is that there is always only one solution to a puzzle.