Learn Sudoku
Learn the logic behind Sudoku one step at a time — from your first placement to advanced solving techniques.
Short lessons. Interactive examples. Real practice.
Your Sudoku path
From the rules to advanced solving
Work through the path in order, or open a lesson directly when you want to practice a specific idea.
Module 0
Orientation
1 lessonModule 1
Foundations
3 lessons- L-002The GridIdentify cells, rows, columns, boxes, and peers in a classic Sudoku grid.
- L-003The RulesDecide whether a proposed digit placement is legal under classic Sudoku row, column, and box rules.
- L-004Your First MovesSolve simple cells by identifying the only missing digit or only legal position.
Module 2
Beginner Solving
5 lessons- L-005ScanningUse a deliberate scan of units and digits to identify promising forced placements.
- L-006CrosshatchingUse existing copies of one digit to block rows and columns and find that digit's only position in a box.
- L-007Naked SinglesIdentify and solve a cell that has exactly one legal candidate.
- L-008Hidden SinglesIdentify when one digit has only one possible position in a row, column, or box.
- L-009Beginner PracticeChoose between scanning, Naked Singles, and Hidden Singles in mixed beginner puzzle states.
Module 3
Candidates
2 lessonsModule 4
Intermediate
7 lessons- L-012Locked CandidatesRecognize when one digit is confined to a box-line intersection and identify the correct elimination direction.
- L-013Pointing PairsFind a digit confined to one row or column inside a box and eliminate that digit from the line outside the box.
- L-014Box-Line ReductionFind a digit confined to one box within a row or column and eliminate that digit from the rest of the box.
- L-015Naked PairsRecognize two cells that reserve exactly two digits and eliminate those digits from other cells in the shared unit.
- L-016Hidden PairsFind two digits that are restricted to the same two cells in a unit and remove all other candidates from those cells.
- L-017Sudoku TriplesRecognize Naked and Hidden Triples as three-cell / three-digit subset reservations and apply the correct eliminations.
- L-018Intermediate PracticeChoose and apply intermediate eliminations without technique labels, then use the resulting simpler deductions to continue.
Module 5
Advanced Patterns
5 lessons- L-019X-WingRecognize a size-2 Fish for one digit and eliminate that digit from the cover units.
- L-020SwordfishExtend Fish logic to three base and three cover units.
- L-021XY-WingIdentify an XY pivot and two pincers, then eliminate the shared Z candidate from common peers of the pincers.
- L-022XYZ-WingRecognize an XYZ pivot with XZ/YZ pincers and eliminate Z from common peers of all three pattern cells.
- L-023Skyscraper & Two-String KiteRecognize two common short single-digit patterns built from conjugate pairs.
Module 6
Links & Chains
4 lessons- L-024Strong and Weak LinksDistinguish Strong and Weak Links and propagate their basic true/false implications.
- L-025How Chains WorkTrace a simple alternating inference chain and understand how endpoint conclusions create eliminations.
- L-026W-WingUse an external Strong Link to connect two matching bivalue cells and eliminate their other candidate.
- L-027Unique RectanglesUnderstand the unique-solution assumption, identify the four-cell deadly rectangle geometry, and apply Unique Rectangle Type 1.
Module 7