How to Play Sudoku

Sudoku is a 9×9 logic puzzle. You fill the empty cells so each row, column and outlined 3×3 box contains the digits 1 through 9 exactly once.

Make your first move

  1. Find an empty cell in a row or box with several given digits.
  2. Cross off the digits already present in its row, column and box.
  3. If only one digit remains, write it in the cell. Otherwise, keep the remaining numbers as pencil notes and inspect another cell.

Given digits stay fixed. A move is justified by the constraints, so you never need to guess.

When scanning is not enough

A naked single is a cell with one remaining candidate. A hidden single is a digit with only one possible place in a row, column or box, even if that cell has other candidates.

Try these deductions in a free Easy Sudoku puzzle. Use the Notes button to track candidates, or move to Medium Sudoku when you are ready for more candidate work.