🔰 Basic Sudoku Techniques for Beginners

New to Sudoku? Start here! Learn the most important techniques every beginner must know—explained with examples and practical tips.

✅ Why Learn Basic Techniques First?

Before jumping into complex patterns or rare tactics, mastering the core solving strategies is essential. These basics help you confidently fill in cells, avoid early mistakes, and enjoy faster solving as puzzles get harder.

📌 Naked Single

If a cell has only one possible candidate, it's a Naked Single. You can write that number in immediately. This often happens in easier puzzles or after solving parts of harder puzzles.

Tip: Always scan rows, columns, and boxes for cells with just one remaining option.

📌 Hidden Single

Sometimes a number is possible in multiple cells, but within a row, column, or box, only one cell can actually take it. That's a Hidden Single.

Example: In a row, if only one cell can be a 7—even if other candidates are present—it must be 7.

📌 Pencil Marks (Candidate Notes)

Use pencil marks to note possible candidates in empty cells. As you solve, eliminate candidates from other cells to narrow down possibilities.

This helps you visualize the logic and spot techniques like Naked or Hidden Singles faster.

📌 Cross-Hatching

A scanning method: Look at each number (1–9) and eliminate boxes/rows/columns where it already appears. Then find where it must go.

Best Used: In early stages to fill in obvious placements.

📌 Box-Line Reduction (Preview)

Sometimes a candidate in a box appears only along one line (row or column). This allows you to eliminate that candidate from the rest of that line outside the box.

This technique borders intermediate level but can appear early.

🎯 Practice These Techniques

The following puzzle is beginner-friendly and ideal for applying what you’ve just learned.

📚 Continue Learning

• Next: Intermediate Strategies →
• 🧩 Beginner Sudoku Book (Level 1–8)
• 🎯 Medium-Hard Book (Level 9–12)