There is a rumour that it is possible to win The Citadel of Chaos without rolling dice. This isn't true - you must do battle at least once. Towards the end, there is a hydra you can fight. It is possible to avoid fighting the hydra if you have the golden fleece, but to get that you need the silver comb, and to get that you need to fight and kill s Gark.
The Internet would have you believe that you have to kill the bonekeeper in Crypt of the Sorcerer. You don't. In fact, absolutely nothing good comes of attacking him.
A rumour persists that Legend of Zagor was actually written by Keith Martin and not Ian Livingstone because of how little it resembles Livingstone's usual gamebooks; rather than requiring the player to follow one specific path to win, it is more like Martin's in that it keeps track of previous events and many of the encounters are optional.
Nearly every book in the series has 400 references (although there are a number of exceptions, ranging from Starship Traveller with 343 (the last three references are all explanations of the combat system) to Howl of the Werewolf with 515). This number was hit upon when it was discovered that the completed version of the first book, The Warlock of Firetop Mountain, had 399 references; Steve Jackson added an extra reference (supposedly not reachable and there solely to make up the numbers) to round things up.