What Is Sudoku?

Sudoku is a logic puzzle. The goal is to fill a 9x9 grid so that every row, column, and 3x3 box contains all numbers from 1 to 9. All without repeating any number in each row, column, or box.

The 4 Golden Rules

1. Each row must have the numbers 1 to 9
   No repeats. Every number appears once.
2. Each column must have the numbers 1 to 9
   Again, no duplicates.
3. Each 3x3 box must have the numbers 1 to 9
   There are nine 3x3 boxes in the full grid. No repeating numbers in each one.
4. Use logic, not guessing
   You should be able to solve a good Sudoku with deduction only. No need to guess randomly.

Helpful Tips To Get Started

• Look for easy wins: Start with rows, columns, or boxes that already have many numbers filled in.
• Cross-check: If you place a number, check that it doesn't break any of the rules.
• Pencil marks: If you're not sure, note possible numbers in a cell to narrow it down later.