The Joker is a character portrayed by Heath Ledger and the main antagonist in Christopher Nolan's 2008 superhero film The Dark Knight. Based on the DC Comics supervillain of the same name, he is depicted as a psychopathic criminal mastermind with a warped, sadistic sense of humor who defines himself by his conflict with the vigilante Batman. In the film, the Joker tests how far Batman will go to save Gotham City from descending into chaos by targeting the Caped Crusader's allies, including police lieutenant James Gordon and district attorney Harvey Dent. Ledger's portrayal of the Joker as an avatar of anarchy and chaos was specifically influenced by the graphic novels Batman: The Killing Joke and Arkham Asylum: A Serious House on Serious Earth. He wears the character's traditional purple and green color palette, while his disfigured clown-like appearance is the result of smeared makeup that covers the facial scars of a Glasgow smile (rather than bleached white skin from falling into a tank of chemical waste, like in the source material). Paintings by Francis Bacon, the character of Alex in Anthony Burgess' novel A Clockwork Orange and Stanley Kubrick's film adaptation of the same name, and various punk rock musicians served as additional inspirations for Ledger's performance.
