1. Fill the grid so that the numbers 1 through 9 appear in each row. 2. Fill the grid so that the numbers 1 through 9 appear in each column. 3. Fill the grid so that the numbers 1 through 9 appear in each 3x3 box. 4. A complete Sudoku puzzle contains the numbers 1 through 9 in every row, column, and 3x3 box.
The same rules apply to monster mode:
