Step-by-step walkthroughs
Every logic puzzle in our books comes with its own walkthrough. Scan the QR code next to a solution and you see that exact puzzle solved one move at a time: the cell, the digit, and the technique that proves it. Here is a sample puzzle (not from any book) to try.
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.
How to use them
Check one step, not the whole answer. Press Next until the walkthrough reaches the point where you got stuck. Stop there and carry on yourself.
Skip the easy parts. “Skip to next hard step” jumps past the singles to the move that unlocks the grid.
Learn the technique. Each step names its technique and explains it in a sentence. The same handful of ideas comes up again and again.
Private links
Each walkthrough has its own long, random address, and the only way to it is the code printed in the book. They aren't listed anywhere or indexed by search engines, so nobody stumbles on your answers.
We count scans (just the number, nothing about you) so we know the walkthroughs are useful.