Su Doku took the world by storm in 2004 when Wayne Gould published his first series of puzzles in The Times. Marking 20 years since this phenomenon Wayne has hand-selected 300 of his original puzzles for this special anniversary collection.

During a visit to Japan, Wayne was in a bookstore where, not knowing how to read or speak Japanese, he was drawn to the puzzle which he first thought was a crossword. He was intrigued and later on he decided to take it with him to the United States and Britain. After his initial retirement, in efforts to pass time and sharpen his computer skills, Gould developed a computer program that generates Su Doku puzzles.

The rest is history, Su Doku became a massive hit around the world and continues to challenge minds to this day with The Times at the forefront of Su Doku publishing in print and online.

Enjoy this selection of Wayne's original puzzles from 2004-5.

Easy, Mild, Difficult and Fiendish puzzles included.