The rules of Diagonal Sudoku Samurai X Gattai-5 sudoku: Each Samurai Sudoku puzzle consists of 5 overlapping 9×9 Sudoku sub-puzzles Each 9×9 sub-puzzle must be solved according to the rules of Sudoku: each row, column and 3x3 "nonet" must contain all digits from 1 to 9. Therefore, digits cannot be repeated in them. Digits cannot be repeated on the diagonals, either. The diagonals are drawn in each puzzle; there are 10 of them altogether and each diagonal consists of precisely 9 numbers, so every diagonal must contain all digits from 1 to 9. Each 9×9 sub-puzzle when solved individually could have more than one solution. DO NOT ATTEMPT to completely solve each 9x9 sub-puzzle as an individual puzzle. Never resort to guessing. My puzzles can be solved using deduction logic. Each Samurai Sudoku puzzle has one solution only. There are 100 puzzles in this book and they are evenly split across 5 levels of difficulty. Enjoy!