The 39 Clues/YMMV


 * Alternative Character Interpretation: Is Alistair Oh an old man who genuinely cares for Amy and Dan and feels regret for, or a backstabbing enemy who feels no remorse for his betrayals?
 * Ian Kabra tends to be subject to this for several reasons, but since his, the question of his true nature is definitely up for debate.
 * Broken Base: The trading cards and website, especially the cards. Why? In the opinion of many fans, the pictures of the characters on the trading cards do not live up to the characters' descriptions in the books or the way that readers imagined the characters to look like, or else simply do not look appealing (a common complaint is that Ian and Evan look too much like Justin Bieber). The rest of the fans either like the pictures on the trading cards, or just like the trading cards and couldn't care less about what the pictures look like.
 * When the official message boards were made canon in The Dead of Night, some fans blew a gasket. Others eagerly played along with Evan's posts on the message boards. It's hard to find someone without a clearly defined opinion on this development...
 * Complete Monster: In In Too Deep we finally meet the charming
 * Damien Vesper.
 * Die for Our Ship: Fans of Amy/Ian have been known to behave extremely aggressively towards any and all opposing pairings, bashing Hamilton, Kurt, and Evan, complete with a plethora of Revenge Fic for the latter two.
 * Shippers of Hamilton/Sinead and Jonah/Sinead do not often get along, for this very reason.
 * Fanon: And a good amount of it, too.
 * It is difficult to find a fan who does not believe that the infamous Kurt, who appeared in one book and was never seen again, was an undercover Vesper.
 * A friend of Amy and Dan's Uncle Shep was mentioned once in the first series. But due to his name and the revelation that , people not only believe that this friend is probably a Vesper, but that Evan Tolliver is related to Vespers as well (if not a full-blown undercover agent). This fandom sure does love its Epileptic Trees...
 * Since the revelation of Isabel Kabra's maiden name and of the fact that Arthur Trent , a great deal of fanon involving them has sprung up. It's taken for granted that they interacted with each other when younger, and many fans believe that they were romantically involved, though there is no canon basis for this.
 * Quite a few fans are absolutely convinced that Amy's full name is Amy Hope Cahill.
 * It's generally accepted that Amy and Dan got their green eyes from their mother, and although Canon gives no evidence supporting this theory.
 * Foe Yay: Seeing as most of the main characters are adolescents caught up in centuries-old feuds, this is eveywhere. Mostly between, but it can be seen between other clue hunters, too.
 * I thought Foe Yay was supposed to be subtext.  are practically the Official Couple.
 * God Mode Sue: What you will become if you drink the master serum.
 * Jerkass Woobie: Ian and Natalie become this after they undergo a lot of Character Development. And their scary mother shows up.
 * Nightmare Fuel: Cahills Vs. Vespers, big time. The biggest one so far is from Vespers Rising, where an Elite Mook by the name of Bruno
 * Ron the Death Eater: Quite frequently for Evan Tolliver and Kurt. The most commonly found demonization is making them turn out to be undercover Vespers, but fanfiction involving Evan suddenly dumping Amy is also becoming common.
 * Luke Cahill is sometimes treated this way, for no apparent reason other than he liked to sneak around more than his siblings. He did also become somewhat of a Jerkass in his later years, but he was never evil.
 * The Woobie: Dan and Amy.
 * At least towards the end of the series,