Featuring a huge number of Kropki Sudoku puzzles, all carefully sorted into order of increasing difficulty, this second unique collection of 200 puzzles is full of attractively-designed challenges from best-selling puzzle author Gareth Moore, author of many international books. Kropki Sudoku adds circles between squares which indicate two different types of relationship: consecutive values, and doubled values. Specifically, a black circle marks all adjacent squares where the value in one is double that in the other, such as 3 and 6; and a white circle indicates all numerically-consecutive adjacent squares, such as 3 and 4. The initial grids are empty and it's up to you to use the circles - and the lack of circles - to fill-in every square of the otherwise standard Sudoku puzzle Printed on large, top-quality paper ideal for solving on, the 200 Kropki Sudoku puzzles vary in difficulty from easy to extremely hard so whatever your preference or experience you'll always find a puzzle here to suit you. Visit www.PuzzleBooks.org for a full list of other titles in this series.