Rules of Sudoku

Sudoku is a number puzzle game played using 81 squares laid out on a 9×9 grid. The grid is further broken down into 9 3×3 boxes. When you start a sudoku puzzle, some of the numbers will have already been placed. All you have to do is fill in the missing numbers by following some simple rules:

  1. Every box must contain each number 1-9. The boxes are 3×3 grids and their outlines are marked with thicker line.
  2. Every row must contain each number 1-9
  3. Every column must contain each number 1-9

Each sudoku board has only one solution, which means that each square has only one possible correct number. This allows you to use logic to find the correct number to place in each square. You can find the correct number to write either by eliminating every other number as a possibility or by eliminating that number as a possibility in that square’s shared row, column, or box.

When you start a puzzle, it will look like something this:

Some of the squares have values, your job is to fill in the blank squares.

When solved, the puzzle will look like this:

Solved puzzle
Notice how every row, column, and box contains every number 1-9.

If you would like to play this puzzle, go ahead and play it now.