
Welcome to volume 4 of this extraordinary collection of Sudoku Variants puzzles
There are 75 Variations of Sudoku in this book. Two puzzles of each kind, one of the relatively easy, one relatively difficult, for a total of 150 fantastic puzzles. There are also a few surprises...

The Encyclopedia of Grid Logic: 75 Distinct Types in One Volume Master the complete taxonomy of logic with Sudoku Variations Volume 3. This collection is the definitive proving ground for solvers who have outgrown standard grids. It features the same high-intensity logic...