YMMV / Xanth

• Damsel Scrappy: Millie in Castle Roogna. She does nothing useful throughout the plot, and her only reaction to danger is screaming and kicking her legs. We find out later that Millie acts this way on purpose because she was under the impression that that's the way a proper maiden behaves.
• Fridge Brilliance: The omnipotent entities that control all of reality and whose true names can only be expressed as equations are referred to as Demons, not Gods. Gods (ostensibly) care about the people within their sphere of influence. Demons do not.
• Nightmare Fuel: What Trent found in Castle Roogna's library in the first book.
• No Problem with Licensed Games: The Adventure Game based on one of the novels managed to be at least halfway decent. The novel is based off of the game that is based off the novel. It's maddeningly recursive on Your Head A-Splode levels. Basically, in the novel, the protagonists are playing the game that is now out, based on the novel, making it a bit of I Wish It Were Real, as well. The Author's Note straightens this out: Anthony wanted to make a Xanth computer game, but lacked the expertise to do it himself. He wrote the novel to show Legend Entertainment what the Xanth game should be like, and they went and made it for him.
• Pandering to the Base: Xanth is read mostly by hormonal teenagers (of both genders), and Piers Anthony is distinctly aware of this — and includes a weird combination of fanservice and active female characters for both sides.
• Periphery Demographic: Young kids and teenagers, actually, due to the puns. Funnily enough, Anthony stated in one of his Author's Notes that the reason the Adult Conspiracy was hiding less in later books was that he was offended that his books were being put in the Teens section of the library and wanted to emphasize that the books were meant for adults.
• Seasonal Rot: There are effectively "seasons" to the books, which can be judged by the protagonists and their connections to the royal family. About the time the series starts wandering further and further afield of Bink's direct descendants, it becomes obvious that Anthony is just writing to meet his word count, with entire chapters of Filler that either have no effect on the overall story or just serve to transparently and hamhandedly introduce characters or situations for a later book.
• Sequelitis: And how. The first book was amazingly original, but by Harpy Thyme the prose is so badly written it can be painful to read in places, among other problems. Many people recommend stopping by Question Quest, and giving the later books a miss except those with characters from the early series (like the aforementioned Harpy Thyme, sadly).
• Theiss Titillation Theory: As with most Anthony books, characters who are fully clothed and characters who are fully nude are treated about the same. Characters who are partially nude, or seem to be inches from nudity, are so dangerously sexual that it can cause men to Freak Out at the very sight.
• What Do You Mean, It's Not for Kids?: An averted example. The series starts out very clean-cut. There's violence, and there's off-screen sex, but no more than most fairy tales. Then, the author found out that his books were being put into the kid's section and he had the "Adult Conspiracy" break down and the books became more explicit.

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