Rules & basics
Start here — how each variant works, why the rules exist, and how to read a grid without the basic stuff getting in your way.
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Articles on Sudoku — the techniques that crack expert puzzles, the history of the game, and the honest version of what daily play does and doesn't do.
Recent articles
History & culture
A short history of Sudoku X
Where Sudoku X (Diagonal Sudoku) came from, how it spread alongside the 2005 Sudoku boom, and what its quietly steady following looks like today.
4 min read
History & culture
A short history of Windoku
Where Windoku (the original Dutch name for Hyper Sudoku) came from, how it spread, and why it's quietly maintained a thirty-year following in puzzle publishing.
5 min read
Techniques
Forced diagonal cells
The signature technique of Sudoku X / Diagonal Sudoku — a cell on the X where row, column, box, and diagonal together force the digit, even when no single constraint does.
4 min read
Variants
How Hyper Sudoku differs from classic
For solvers who already play classic Sudoku — what changes mentally when you switch to Hyper Sudoku (Windoku), and what carries over unchanged.
4 min read
Variants
How Sudoku X differs from classic
For solvers who already play classic Sudoku — what changes mentally when you switch to Sudoku X (Diagonal Sudoku), and what stays exactly the same.
4 min read
Categories
Techniques
Naked pairs, hidden singles, X-wings, cage combinations — the logic patterns that separate easy puzzles from expert ones.
View all →Variants
Beyond Classic: how Killer, Kakuro, and other cousins change the constraints and the kind of thinking each one rewards.
View all →Habit & wellness
The research on focus, working memory, and why a daily puzzle habit sticks better than most brain-training apps.
View all →History & culture
Where Sudoku came from, how it spread, and the people who shaped how the puzzle is solved today — Maki Kaji, Howard Garns, the variants tree.
View all →For specific solvers
Sudoku tuned to a specific kind of player — kids learning the rules, classroom teachers, parents on long drives, older adults who enjoy a daily puzzle, anyone who wants the writing pitched at them.
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