How to Play Sudoku

1. 1. The Grid

   Sudoku is played on a 9×9 grid, divided into nine 3×3 boxes. Some cells contain given numbers (clues).

2. 2. Row Rule

   Each row must contain the digits 1-9 exactly once. No digit can repeat in a row.

3. 3. Column Rule

   Each column must contain the digits 1-9 exactly once. No digit can repeat in a column.

4. 4. Box Rule

   Each 3×3 box must contain the digits 1-9 exactly once. No digit can repeat within a box.

5. 5. Unique Solution

   Every valid Sudoku puzzle has exactly one solution. Use logic, not guessing!

Cyan numbers are given clues. Fill empty cells with digits 1-9.

• Scan for singles — Look for rows, columns, or boxes missing just one digit.
• Use pencil marks — Note possible candidates in empty cells to track options.
• Look for naked pairs — Two cells with the same two candidates can eliminate those from other cells.
• Check intersections — Where a row/column intersects a box, one may constrain the other.
• Work systematically — Focus on one digit at a time, finding all its placements.
• Never guess — Every Sudoku has a logical solution. If stuck, look for patterns.