Free sample from Extreme Sudoku 3: step-by-step solution

Print the puzzle first (PDF, A4 or US Letter), then come back and step through the solution, or skip to the hard parts.

Puzzle: Sudoku, the free sample for Extreme Sudoku 3 (not one of its 150)
Difficulty: Expert 6 (expert and beyond)
Key technique: Nice Loops/AICs
Hard steps: 18 of 42 steps need an advanced or expert technique

Show pencil marks

Blue digits are placed by the walkthrough. Red strike-through marks a candidate being ruled out. Cells are named by row and column: R3C5 is row 3, column 5. Arrow keys step too.

The key technique: Nice Loops/AICs

An alternating chain of strong and weak links. Whichever end is true, the conclusion holds, so the digit at the marked cell is ruled out.

Every move above the basics is explained on the sudoku techniques page. The book's own 150 puzzles each have a page like this one: all Extreme Sudoku 3 solutions.

The book

Volume three: 150 new classic 9×9 grids, none repeated from books 1 or 2, ramping from hard to brutal.

On Amazon from 8 Dec About the book

Try a free sample puzzle (PDF) · prints on A4 or US Letter