* AuthorsSavingThrow: In the movie adaptation, Langdon has an entire speech where he remembers a near-death experience from his childhood, and seems convinced that he survived because he prayed to Jesus to keep him alive. Since the speech wasn't in the book, it may have been added to placate Christian viewers who were upset that the story questioned Jesus' divinity. Note that Langdon definitely isn't a [[HollywoodAtheist hardline atheist]] in the books, but he's rather ambivalent about religion, and he claims that he's had no genuine religious experiences.
* FollowTheLeader: Created an explosion of AncientConspiracy quests ''*cough* Film/NationalTreasure *cough*'' and books about the Holy Grail. Also, this was was inspired by a [[VeryLooselyBasedOnATrueStory "nonfiction" book]] which is about a conspiracy theory similar to the one Langdon runs into.
* GeniusBonus:
** In Leigh Teabing's library, he has a statue of Janus - the god with two faces. [[spoiler: This foreshadows that Leigh himself is two-faced and will betray them]].
** Bishop Aringarosa's name is made up of the words 'aringa' and 'rosa', which can be translated from Italian to mean RedHerring.
* HoYay: Silas and Aringarosa. Fache and Collet. The first seems to go both ways. The second is more of a case of Collet sorta worshiping Fache and Fache, at first, thinking him not-so-great. The book and film go about it differently, but at the end of each, Fache's opinion of Collet has somewhat improved.
* JerkassWoobie: Silas may be violent and somewhat unstable, but he's had a ''really'' shitty life. [[spoiler:By the time he repents, he dies not long after]].
* {{Narm}}: Towards the end of the movie version, Langdon has a speech where he recalls nearly drowning in a well as a child, and praying to Jesus to keep him alive ("Sometimes I wonder if I wasn't alone down there!"). It's not necessarily badly written, but it has basically ''no'' relation to any other theological topic that comes up in the movie, and it was pretty obviously [[AuthorsSavingThrow stuck in to deflect claims that the original book had an atheist message]]. "Oh, Christians are angry that the story questions Jesus' divinity? Well, we better shoehorn in a speech where the hero claims that prayer saved his life..."
* OlderThanTheyThink: The idea of an American man and a French woman uncovering a conspiracy involving the Knights Templar and its modern day secret society in Europe was first implemented in ''VideoGame/BrokenSword: The Shadow of the Templars''.
* TheProblemWithLicensedGames: The Game Of The Movie was a combination beat-em-up / puzzle game with a laughably {{Narm}}tastic script.
* SnarkBait: It seems that a less-than-shiny book assembled from moldy pieces of cryptohistory is ''not'' going to be any less of a target if advertised as a daring innovative idea and (whispering) maybe even a ''really'' relevant theory.
** The fact that it holds the [[http://www.bbc.co.uk/news/entertainment-arts-14006782 record]] for the most frequently donated book gives way to a lot of Snark Bait.
* StrawmanFallacy: In the film discovering descendants of Jesus is treated as something that would destroy the Catholic church, and [[spoiler: Teabing and the Piory]] wants to bring down the Church for centuries of persecution and deceit. This is a straw argument for several reasons. Christ's divinity and spiritual authority did not come from human genes, so there's not reason to think his spiritual power can be passed on by them. In addition, God being infinite, it would not be diluted across His descendants; not to mention being Christian cannot be inherited from one's parents, it requires a personal decision. Proving that Jesus had a wife and descendants would be a remarkable finding that would cause a stir, but marriage is a God-ordained union, a sacrament in the Catholic Church and a central feature of Christianity so it would not do what the film claims it would do. [[RuleOfCautiousEditingJudgment And we'll leave it at that.]]
* WhatCliffHanger: The book had a OneParagraphChapter in which Robert Langdon and his date see a thing inside a box. Whatever the grail was, it wasn't ''that thing'' [[spoiler: (the thing turned out to be a cryptex, i.e., a tube that had a puzzle to be solved for it to open)]]. In fact, done frequently in anything written by Dan Brown. It's pretty much the end of every chapter.
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