Category
Logic
Sudoku, nonograms, logic grids and every deduction puzzle in between - how they work and how they are built.
Nonograms Are Pixel Art You Solve With Arithmetic
How to read the clue numbers, where beginners stall, and three techniques that unlock harder grids.
Sudoku Variants That Are Worth Your Time
Killer, thermo, arrow and sandwich: which twists add real deduction and which just add rules to memorise.
Logic Grid Puzzles and the Zebra Problem
Five houses, five nationalities, five drinks. The puzzle that taught a generation how to think in constraint tables, and how to build your own.
How a Puzzle Proves It Has Exactly One Solution
Uniqueness is the quiet contract behind every good logic puzzle. Here is how setters actually check it, and what happens when they do not.
Kakuro Killer and the Arithmetic Puzzles That Are Not Sudoku
A whole family of puzzles runs on sums rather than symbols. The combinations worth memorising, and why they open grids faster than any scanning technique.
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One good puzzle a week. No filler.
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