The Clue series is a book series of 18 children's books published throughout the 1990s based on the board game Clue. The books are compilations of mini-mysteries that the reader must solve involving various crimes committed at the home of Reginald Boddy by six of his closest "friends".
Each book begins with a small chapter where Mr Boddy introduces himself to the reader. He explains the situation and introduces the six suspects. This ends with some kind of cliffhanger that leads into the first chapter.
Except for the first book, which contains thirteen, all the books contain ten mini-mysteries similar to the Encyclopedia Brown books. Each mystery ends with a question to answer, and a picture of the checklist from the game is provided to assist with solving. The answer is printed upside-down on the next page, providing an explanation of how the criminal was foiled, or how the victim (if there was one) survived. The first nine mysteries typically involve some sort of competition between the guests (in which case readers must deduce who won), a guest attempting to murder another guest, or some sort of rare treasure of Mr Boddy's that has been stolen. Deduction of the guilty party is done by tracking particular oddities given specific to the mystery, such as the guests all trying on specific scents of perfume or a note that some are wearing a particular style or color of clothing. The guests also have very distinct, exaggerated personalities that betray their identities to the reader when they are not directly named.
Someone attempts to murder Mr Boddy in the final chapter of each book. In the solution, no explanation is given, and it is suggested that Mr Boddy actually dies. In the introduction of subsequent books, however, Mr Boddy explains how he survived the end of the previous book, with the exception of the eighteenth book. This allows the series to come to an end at any point without ending abruptly and also leaves it open for another book.
Except as noted, the original hardcover editions were published by Turtleback Press, and had four different authors. Later paperback reissues are credited "Book created by A.E. Parker", and are published by Scholastic Press. The series is currently out of print. ISBNs are for the paperback reissue.
See main article: List of Cluedo characters. With the exception of Mr. Boddy, the six central characters' faces were featured prominently on the back cover of each book, with three randomly selected to appear in an illustration created especially for the cover of each book. Books 1-4 feature the characters as they appeared in the 1986 edition of the board game. From Book 5 onwards, the character redesigns from the 1992 edition were used.
In 2003, Canadian mystery writer Vicki Cameron wrote a new set of mini-mysteries, the Clue Mysteries books, after the original author, Nigel Tappin, backed out of the project. Only two were published. Both books feature more complex storylines and vocabulary, fifteen mysteries apiece. The setting is at the fictional mansion Tudor Hall in Hampshire, Britain in 1926. The stories are formatted to be more like the game, with each mystery being about the murder of Boddy and featuring one guest conducting the entire investigation before accusing another guest of the crime.
In 2008, a book called "CLUE" code breaking puzzles", was released.