Book excerpt: Featuring a huge number of Killer Sudoku Zero puzzles, all carefully sorted into order of increasing difficulty, this unique collection of 200 puzzles is full of attractively-designed challenges from best-selling puzzle author Gareth Moore, author of many international books. Killer Sudoku Zero puzzles are similar to Killer Sudoku except that all unnecessary cages are removed. The cages that remain give the sum of the values in the squares which they cover. Printed on large, top-quality paper ideal for solving on, the 200 Killer Sudoku Zero puzzles vary in difficulty from easy to hard so whatever your preference or experience you'll always find a puzzle here to suit you. Search '200 Puzzles Moore' on Amazon for lots more titles in this series, including regular Killer Sudoku.