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. Read → 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. Read → 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. Read → 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. Read → 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. Read → 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. Read → How to Play Sudoku With Friends — Online Rooms, Races & Family Games Play Sudoku with friends and family: set up an online room in three steps, share one link, and race the same puzzle in real time — plus fair-play tips for mixed skill levels. Read → Get Cubedoku as an App — Add to Home Screen on iPhone & Android Turn Cubedoku into a home-screen app in under a minute — no app store, no download. Step-by-step for iPhone, iPad, Android and desktop. Read → Easy to Expert — How to Choose the Right Sudoku Difficulty What Sudoku difficulty levels actually measure, a 30-second self-test to find your tier, and a simple rule for when to move up to the next level. Read → Sudoku Variants Explained — From Killer to 3D Cubes A map of six ways to play Sudoku — Classic, Killer, Skyscraper, 3D Cube, Avalanche and Blitz: what each variant trains and which to try first. Read → 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. Read → 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. Read → 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. Read → Combinaisons du Sudoku Killer — l’antisèche complète Chaque somme de cage du Sudoku Killer et ses combinaisons possibles, des cages de deux à cinq cases, plus les 16 cages forcées et la règle de 45. Read → Skyscraper Puzzle Techniques — Five Tools Beyond the Basics Stop guessing at Skyscraper puzzles: the staircase bound, opposite-clue interaction, visibility counting and the Latin-square crossover, with a worked line. Read → How to Solve Sudoku Faster — Speed Training That Works Fast solvers recognise, slow solvers reason. Three drills that build recognition, how to use timers without panic, and what fast actually looks like. Read → Sudoku Glossary — Every Term from Naked Single to Swordfish Plain-language definitions of every Sudoku term: units and candidates, singles and subsets, fish and wings, Killer cage vocabulary and Cubedoku modes. Read → 10 Common Sudoku Mistakes (and How to Stop Making Them) From guessing to stale pencil marks: the ten habits that quietly ruin Sudoku boards, why each one hurts, and the one-at-a-time way to fix them. Read → Brain training & benefits Can Sudoku Help Prevent Dementia? An Honest Look at the Science What research really says about puzzles and the aging brain — the PROTECT study, the ACTIVE trial, cognitive reserve, and why spatial 3D puzzles stand out. Read → 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. Read → 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. Read → Sudoku en gros caractères gratuit pour seniors et grands-parents (imprimable) Sudoku en gros caractères gratuit pour seniors et grands-parents : des chiffres grands et nets à imprimer chez vous ou à jouer en ligne. Sans inscription, sans appli, avec les solutions. Read → 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. Or play with friends in multiplayer Sudoku .
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 .
