Sudoku Guides
Rules, solving techniques, and the case for puzzles as brain training.
Cubedoku is a free logic-puzzle game with six ways to play Sudoku — from a classic 6×6 grid to a fully three-dimensional 9³ cube. These guides cover everything written for humans, not search engines: how each mode works, the techniques that take you from beginner to Expert, and an honest look at what puzzle habits do for your brain. Whether you're six or sixty-plus, there's an entry point here — Sudoku needs no reading level, no trivia and no reflexes, which is what makes it one of the few games a whole family can share.
How to play
- How to Play Classic Sudoku — Rules from 6×6 to 25×25 — Classic Sudoku rules explained simply: rows, columns and boxes from beginner-friendly 6×6 up to giant 25×25 grids. A complete starter guide for all ages.
- How to Play The Cube — 3D Sudoku on a Rotating Cube — The Cube wraps Sudoku around all six faces of a 3D cube. Learn how shared edges work, what changes from 3³ to 9³, and how to think spatially.
- How to Play Skyscraper Puzzles — Rules and First Steps — Skyscraper puzzles combine Latin squares with line-of-sight clues. Learn the rules, the classic opening deductions, and how sizes 4×4 to 12×12 differ.
- How to Play Avalanche — Collapse the Cube Block by Block — Avalanche splits a big cube into 3³ sub-cubes that collapse as you complete them. Rules, strategy, and why it feels like Sudoku meets match-3.
- How to Play Blitz — Sudoku Where the Clues Disappear — In Blitz, a starting clue vanishes every few seconds — filling a cell resets the timer. Learn the rules and how to stay calm under pressure.
- How to Play Killer Sudoku — Cages, Sums and the Rule of 45 — Killer Sudoku rules explained: cages with sum clues, unique combinations, innies and outies, and the rule of 45 — plus a sensible solving routine.
Solving techniques
- Sudoku Tips for Beginners — 7 Habits That Make You Faster — Start solving with confidence: scanning, naked singles, hidden singles, and pencil marks explained with simple examples anyone can follow.
- Intermediate Sudoku Techniques — Pairs, Triples and Pointing — Stuck on Medium and Hard puzzles? Naked pairs, hidden pairs, pointing pairs and box-line reduction — the four techniques that unlock most grids.
- Advanced Sudoku Techniques — X-Wing, Swordfish and XY-Wing — The pattern-based eliminations behind Expert-level solving: X-Wing, Swordfish and XY-Wing, each broken down step by step.
Brain training & benefits
- Is Sudoku Good for Your Brain? What Logic Puzzles Train — Working memory, concentration, planning — what regular Sudoku practice actually exercises, what the research says, and how to build a daily habit.
- Sudoku for All Ages — A Family Guide from Kids to Grandparents — One puzzle, every generation: which grid sizes suit young kids, busy commuters and seniors, plus tips for playing Sudoku together as a family.
Ready to play?
Everything you just read about is free to play in your browser — no download, no account required. Start a puzzle, or jump straight into today's Daily Challenge and see where you land on the worldwide leaderboard.
About Cubedoku
Cubedoku is an independently built Sudoku game. Every puzzle comes from our own generator and is verified to have exactly one solution, and every guide here is written and maintained by us. The game is free and privacy-first: anonymous play needs no account, and your data stays in your browser. Questions, corrections or suggestions — email support@cubedoku.com and a human will reply. See also our privacy policy and terms of service.