Completely infuriating, yet somehow fun, a day without Sudoku often leaves devotees feeling empty and incomplete. What few realize, though, is that Sudoku was adapted from the ancient Hungarian game of Shitedokua game of letters, not numbers. Each line of a Shitedoku puzzle must contain the lettersof "SHITEDOKU," as does each 9-square boxand just like Sudoku, Shitedoku will tax and infuriate the keenest player."

Shitedoku 2005, Michael O'Mara Books, London

ISBN-13: 9781843171829

Trade paperback