How to Play Sudoku: Rules & Tips for Beginners

Sudoku is a logic-based number puzzle that’s easy to learn but endlessly challenging. Here’s how to play:

Objective

Fill a 9×9 grid with numbers 1–9 so that:

  • Every row contains all digits 1–9 (no repeats).
  • Every column contains all digits 1–9 (no repeats).
  • Every 3×3 box (outlined in bold) contains all digits 1–9 (no repeats).
Sudoku grid example with rows, columns, and 3x3 boxes highlighted

Step-by-Step Guide

1️⃣ Start with the Given Clues

  • Each puzzle begins with some numbers pre-filled. These are your starting points.

2️⃣ Scan Rows, Columns, and Boxes

  • Look for rows, columns, or 3×3 boxes that already have several numbers.
  • Example: If a row has 1, 3, 5, 7, and 9, the missing numbers are 2, 4, 6, 8.

3️⃣ Use “Pencil Marks” (Optional)

  • Lightly write small numbers in empty cells to note possible candidates.
  • Eliminate options as you find conflicts in rows, columns, or boxes.

4️⃣ Find “Naked Singles”

  • If a cell has only one possible number (based on existing digits in its row, column, and box), fill it in.

5️⃣ Move to “Hidden Singles”

  • A number can only go in one cell within a row, column, or box, even if other options seem possible.

6️⃣ Repeat and Refine

  • Update pencil marks as you add numbers.
  • Gradually solve cells using logic – no guessing needed!

Key Rules to Remember

🚫 No Repeats: A number can’t repeat in any row, column, or 3×3 box.
🚫 No Math Required: Sudoku uses logic, not arithmetic.
🚫 No Guessing: If you’re stuck, revisit previous steps – there’s always a logical solution!

Beginner Tips

🔹 Start with Easy Puzzles: Look for grids with 40+ pre-filled numbers.
🔹 Focus on One Number: Scan the grid for where a specific digit (e.g., “5”) can fit.
🔹 Practice Patterns: The more you play, the faster you’ll spot opportunities.

Advanced Techniques (for Harder Puzzles)

  • Elimination: Remove impossible candidates from pencil marks.
  • Subsets (Pairs/Triples): Identify groups of numbers that can only fit in certain cells.
  • X-Wing & Swordfish: Advanced strategies for expert-level puzzles.

Common Questions

❓ Can Sudoku have multiple solutions?
No! A well-designed Sudoku has only one solution.

❓ What if I make a mistake?
Look for conflicts (repeating numbers in rows, columns, or boxes) and backtrack.

Ready to Play?

Generate free printable Sudoku puzzles from our Sudoku Generator and sharpen your skills today!