Guide

How to Play Sudoku

Sudoku is a logic puzzle. You do not need math beyond recognizing digits; the challenge is placing each number in the only position where it can legally fit.

Basic steps

1. Start with a 9x9 grid divided into nine 3x3 boxes.
2. Fill empty cells so every row contains the digits 1 through 9.
3. Check every column for the same 1 through 9 rule.
4. Make sure each 3x3 box also contains each digit once.
5. Use notes for candidates when a cell has more than one possible answer.

Best first move

Look for a row, column, or 3x3 box that already has many filled numbers. The fewer missing digits there are, the easier it is to find a safe placement.