Learn Sudoku
From beginner basics to advanced techniques
Getting Started
Learn the fundamentals of Sudoku
How to Play Sudoku: Complete Beginner's Guide
Learn the basic rules of Sudoku and start your puzzle-solving journey today.
Naked Singles: The Foundation of Sudoku Solving
Learn the most fundamental Sudoku technique - finding cells with only one possible candidate.
Hidden Singles: Finding the Only Option
Discover cells where only one candidate is possible within a row, column, or box.
Essential Techniques
Master intermediate solving methods
Naked Pairs: Eliminating Candidates Together
Learn how two cells with the same two candidates can eliminate those numbers from other cells.
Pointing Pairs: Box-Line Intersections
Use the intersection of boxes and lines to eliminate candidates efficiently.
Box-Line Reduction: Claiming and Intersection Removal
Master the technique of using row and column constraints to eliminate candidates from boxes.
Advanced Strategies
Take your skills to the next level
X-Wing: The Classic Advanced Pattern
Master the X-Wing technique to eliminate candidates using rectangular patterns across rows and columns.
Swordfish: The Three-Line Fish Pattern
Extend X-Wing to three rows or columns for even more powerful eliminations.
XY-Wing: Three Cells That Trap a Candidate
Use three connected cells with specific candidate patterns to make powerful eliminations.
Expert Level
Tackle the hardest puzzles with confidence
Forcing Chains: Following Logical Consequences
Master the art of tracing candidate implications to find eliminations in the toughest puzzles.
Unique Rectangles: Using Puzzle Uniqueness
Leverage the fact that valid Sudoku puzzles have only one solution to make eliminations.