The full catalogue
Every book below is generated and graded by the same solver: one unique solution, reachable by logic, never by guessing. Difficulty is measured by the techniques a puzzle actually needs — you can read exactly what each level means in the techniques guide.
Not sure which one?
Pick what matters most and the list below will narrow down.
No book matches that combination — try clearing a filter.
How the difficulty levels work
A puzzle's level is the cheapest set of techniques that solves it, not whichever pattern happens to be noticed first. Easy needs scanning and singles; Medium adds locked candidates and pairs; Hard adds triples; Expert adds the fish, single-digit and wing patterns; Extreme forces several different advanced patterns in the same grid. Books marked relaxed pace follow the gentler mass-market scale instead.
The Sudoku Challenge Series
Most of the books above belong to one series on Amazon, which lists every volume on a single page.