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How-to-play guides for every puzzle type, illustrated step by step. Pick a puzzle to learn the rules, see a worked example, and start solving.

sudoku

How to Play Sudoku

A visual, beginner-friendly walk-through of Sudoku rules and a step-by-step solve of a 4×4 mini puzzle.

6 min readMaster the grid through the absolute placement of non-repeating digits.

kakuro

How to Play Kakuro

Crossword-shaped sums where every run uses distinct digits. Learn the magic combinations that crack easy puzzles in seconds.

7 min readCross-sums that demand arithmetic agility and pattern recognition.

kakurasu

How to Play Kakurasu

Shade cells whose hidden weights add up to the clue. A binary puzzle that hides surprisingly rich logic.

7 min readComplex spatial reasoning within a compartmentalized geometric field.

hidato

How to Play Hidato

Trace a number-snake from 1 to N where each step moves one square in any direction. Sandwich deductions crack it open.

6 min readNumber every cell so consecutive values form an unbroken chain.

hitori

How to Play Hitori

Shade cells so the unshaded numbers become unique in every row and column — without isolating any white squares.

6 min readLogical elimination to ensure no number appears twice in any row or column.

hashi

How to Play Hashi

Connect numbered islands with bridges. Forced-bridge cascades make easy puzzles fall like dominoes.

8 min readBuild the architectural infrastructure between numbered logic islands.

slitherlink

How to Play Slitherlink

Draw a single closed loop on a dot grid where every clue cell has exactly the right number of surrounding edges.

6 min readA single continuous loop defined by numerical constraints.

kenken

How to Play KenKen

Latin square meets cage arithmetic. Combining row/column logic with sum, product, and difference cages cracks easy puzzles fast.

7 min readThe fusion of arithmetic operations with Latin square logic.

nurikabe

How to Play Nurikabe

Shade a connected sea around numbered islands. Singletons, clue separation, and the no-2×2 rule do the heavy lifting.

6 min readDefine the binary relationship between island and stream.

shikaku

How to Play Shikaku

Slice the grid into rectangles whose areas match the clues. Factorization + grid-edge elimination crack easy puzzles fast.

6 min readPartition the canvas into rectangles dictated by anchored numerals.

numberlink

How to Play Numberlink

Connect pairs of matching numbers with orthogonal paths so every cell is covered and no paths cross.

5 min readTrace non-crossing paths to unite matching pairs across the grid.

sudoku

The Phistomefel Ring: A Hidden Symmetry in Every Sudoku

In 2020 a Sudoku enthusiast spotted a perfect symmetry hiding in every grid — undiscovered for 35 years. Here is how it works.

6 min readMaster the grid through the absolute placement of non-repeating digits.

sudoku

Sudoku Technique: Naked Pairs and Triples

When two cells in a unit share exactly two candidates, those candidates are locked — the foundational subset technique.

6 min readMaster the grid through the absolute placement of non-repeating digits.

sudoku

Sudoku Technique: Hidden Pairs and Triples

The same subset logic, viewed from the opposite angle. Hidden pairs unlock cells where multiple candidates conspire to fit only two cells.

7 min readMaster the grid through the absolute placement of non-repeating digits.

sudoku

Sudoku Technique: The X-Wing

The gateway to advanced Sudoku. Find a single digit constrained to two cells in two rows — eliminate it from the matching columns.

7 min readMaster the grid through the absolute placement of non-repeating digits.

sudoku

Sudoku Technique: The Swordfish

The X-Wing scaled up to three rows by three columns. Same logic, more elimination — and surprisingly common in hard puzzles.

7 min readMaster the grid through the absolute placement of non-repeating digits.

sudoku

Sudoku Technique: The XY-Wing

Three cells, three digits, one elimination across the grid. The first multi-digit chain technique every advanced solver learns.

8 min readMaster the grid through the absolute placement of non-repeating digits.