* ActorAllusion:
** After what Gambol went through with the Joker, Michael Jai White still hates [[Film/{{Spawn}} clowns.]]
** Nestor Carbonell who played Mayor Garcia also played Batmanuel in ''Series/TheTick''.
* AdaptationDistillation: Harvey Dent's storyline is, in no small way, based on the Jonathan Nolan Story 'Memento Mori', which was also the basis for Creator/ChristopherNolan's ''Film/{{Memento}}''. A few of the Joker's speeches are near direct quotes from that story.
** The Joker's entire motivation seems to be a distillation of ''ComicBook/TheKillingJoke'' themes, particularly how one bad day could drive anyone to madness -- something he claims of himself, and tries to force on Batman, Harvey Dent, and Gotham in general.
* AllStarCast: Specifically Creator/ChristianBale, Creator/MichaelCaine, Creator/HeathLedger, Creator/GaryOldman, Creator/AaronEckhart, and Creator/MorganFreeman. Multi-decade spanning name recognition? Check. Critical acclaim? Check. [[RuleOfThree Awards cache]]? Check and the mate.
* BannedInChina: A rare example of self-censorship. Warner Bros. declined to submit it to Chinese film authorities for review, fearing that the portrayal of Lau as a criminal accountant and implication that Hong Kong police were corrupt would cause backlash. However, the film ended up being one of the most bootlegged titles in the country.
* BeamMeUpScotty:
** SelfDemonstrating/TheJoker is often mis-quoted as asking "Do I look like a man with a plan?" when Harvey Dent says that [[spoiler: his (Harvey's) disfigurement and the death of Rachel Dawes]] was part of his (the Joker's) plan, most likely because people associate the rhyming words "man" and "plan". The quote is actually "Do I really look like a guy with a plan?"
** "Why so serious?" isn't really the Joker's catchphrase. He only says the phrase in a fierce tone when pretending to be his dad, and the one time he says it as himself he says it almost sarcastically. He actually chides the mob for ''not'' taking things seriously.
* CastingGag: William Fichtner was cast as the bank manager because of his previous role in the bank heist thriller ''Film/{{Heat}}''.
* DevelopmentGag: When Fox is asked for improvements to the Batsuit, he remarks, "You want to be able to turn your head." Prior to the Dark Knight Trilogy, no physical implementation of the Batsuit allowed the actors to turn their heads.
* DirectedByCastMember: Heath Ledger directed and shot the two home videos the Joker sends to the media (both the one where he tortures and kills the fake Batman, then the one where a captive Mike Engel is forced to read a script of the Joker's demands).
* FatalMethodActing: While Heath Ledger is not an example (he died after his parts were done), the stuntman who crashed the Batmobile during pre-production is.
* GeniusBonus : The Lamborghini Bruce Wayne drives is a Murcielago, which means Bat. So even when he's not in the suit, [[VisualPun Wayne is still driving a Bat-mobile]].
* MethodActing: To prepare for the part of the Joker, Heath Ledger spent six weeks in a motel room in seclusion to delve deep into his intended portrayal of the Joker's psychology.
* MythologyGag: A memorable line from the 1989 ''{{Film/Batman}}'' movie is the Joker's remark that he wants "his face on the one-dollar bill." In ''Dark Knight'''s viral marketing campaign, [[http://asmith50.files.wordpress.com/2008/07/jokerdollar.jpg Joker really did put his face on the one-dollar bill]]!
* TheOtherDarrin: Maggie Gyllenhaal as Rachel Dawes in ''Dark Knight'', replacing Katie Holmes from ''Begins''.
* PlayingAgainstType: One of the reasons people were so skeptical about Creator/HeathLedger playing SelfDemonstrating/TheJoker was that he wasn't known for villainous roles, let alone one of the most psychotic and monstrous characters in fiction, usually playing romantic leads. As we can see from the result, TropesAreNotBad.
* RealitySubtext: Bruce Wayne requesting a new Batsuit from Fox so that he can turn his head and be more agile, was the result of Christian Bale complaining about these problems with his Batsuit from the first movie.
* StarMakingRole: Heath Ledger was far from unknown prior to the film and was well-known as a romantic actor, and had an Oscar nomination on his resume. But his turn as the Joker is remembered as the one that immortalized his legacy after his death and made him into a household name.
* ThrowItIn:
** SelfDemonstrating/TheJoker's SarcasticClapping when Gordon gets promoted wasn't in the script.
** While the scene when SelfDemonstrating/TheJoker blows up the hospital and the explosions suddenly stop, and Heath begins messing around with the detonator until the explosions suddenly start up again was initially credited to his ad-libbing, Christopher Nolan actually wanted [[http://www.starpulse.com/news/Casey_Johnson/2012/07/20/10_things_you_might_not_know_about_bat "a delayed, staggered explosive effect"]] in that scene. Considering that explosion scenes are usually filmed with extreme caution, ad-libbing would not have been allowed in this case.
** A lot of the Joker's mannerisms were developed when Heath Ledger was getting his makeup done, and would scrunch up his face to create different textures for the makeup. The creepy way in which the Joker sucks on his cheeks was one of these.
** When the Joker arrives at Bruce's fundraiser, he walks out of an elevator past Alfred. Michael Caine (playing Alfred) had a line at that point. However, this was his first time seeing Heath Ledger in full costume as the Joker and he was so surprised that he forgot his line, with Ledger walking by as though nothing had happened.
* TypeCasting: Ron Dean playing Mike Wuertz, one of Gordon's detectives. He behaves similarly to his performance as Detective Kelly in ''Film/TheFugitive''.
* WhatCouldHaveBeen: There's some fairly creepy concept art of the Joker before Heath Ledger was cast.

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