Harvey Dent (also known as Two-Face) was Gotham City's amiable and courteous district attorney and one of Batman's strongest allies until Sal "Boss" Maroni threw acid in his face, hideously scarring him. It also fractured his mental state, causing him to become Two-Face, a schizoid criminal mastermind obsessed with duality and the number two. His former good luck charm, a "two-headed" silver dollar with one side deface has been seized on as a reflection of Dent's half-scarred visage. He flips it to decide the fates of his victims. Despite Batman's efforts to reform his former ally, Dent is consumed by his fixation on chance and his crimes are designed to prove out his diametric philosophy.
After the accident, Two-Face's left half of the face is horribly burned to a reddish color, exposing some of the veins. His left side of his hair colorized white or purple, and his left half of the suit is colorized red.
Harvey Dent served Gotham City as District Attorney. He was an ally of Commissioner James Gordon and Batman. While Dent questioned mob boss Sal Moroni in court, Moroni managed to retrieve a hidden flask of acid and threw it on Dent. Batman became aware of that plot, and ran through the courtroom to save Dent, but arrived too late. The acid splashed against the left side of Dent's face, and horribly disfigured it, while the right side was protected by his notepad.
The acid burned far enough through Dent's head that part of his brain was damaged, and made him half psychotic and homicidal. Dent was eventually arrested and committed to Arkham Asylum. Two-Face escaped from his cell on the second anniversary of his arrest, and his escape was discovered by Dr. Burton, who then contacted the GCPD.
Two-Face and his thugs robbed the Second Bank of Gotham. They took hostages and looked like they were going to get away when Batman intervened and stopped the robbery. Two-Face trapped him and a guard inside an acid filled safe, but Batman escaped and saved the horrified guard. Batman pursued Two-Face by boarding his helicopter. However, Two-Face escaped before he crashed his helicopter into the Statue of Justice over Gotham Harbor.
At his hideout, which was split in half like his personality, Two-Face had two henchwomen, Sugar and Spice, who worked for him. Spice favored his 'dark', scarred side, while Sugar favored his 'good' side. Two-Face traveled to the circus looking for Batman. The circus held a fundraiser that was attended by Gotham's elite, and Two-Face concluded that the odds were excellent that at least one of them knew the Dark Knight's identity if they weren't Batman himself-, and he threatened to blow the place up unless his enemy turned himself over (although the subsequent riot in the circus prevented Bruce Wayne from obeying his order). Two-Face was responsible for the origin of Robin because, when The Flying Graysons tried to stop him, they were all killed by him apart from Dick, the youngest Grayson, who went on to join Batman as Robin after he stopped his bomb.
At his hideout, Two-Face met Edward Nygma, who adopted the mantle of The Riddler, where Two-Face initially wanted to kill him for invading his lair, but Riddler stated his case, and Two-Face decided via coin flip whether he killed or allied with him. After his coin landed on heads, Two-Face stole enough money to fund Nygma's company, and the two gained knowledge through The Box and discovered Batman's true identity at Nygma's party. Following that, they traveled to Wayne Manor and the Riddler destroyed the Batcave. Two-Face, on other hand, had his henchmen attack Bruce and Dr. Chase Meridian while he flipped his coin, which kept landing on the good side, and prevented him from doing any wrongdoing. As soon as the scarred side came up, Two-Face fired his pistol at Wayne, which grazed him in the head. Two-Face wished to finish him off, but the Riddler intervened, then they left, kidnapped Dr. Meridian, and left behind a riddle.
At Claw Island, where Two Face hid, Batman and Robin got separated. Robin had the opportunity to kill Two-Face, but didn't want to be like him. Two-Face used that to capture Robin. Two-Face and the Riddler then tried to make Batman choose between Chase and Robin but Batman destroyed The Box, which permanently defeated the Riddler, and saved them both. Two-Face showed up, and was poised to kill them, but Batman reminded him of his coin. Two-Face flipped his coin to decide if he would shoot Batman, but Batman tossed a handful of identical coins into the air. Two-Face panicked and tried to find his coin but stumbled and fell into the pit on a watery bed of spikes. His exact coin then fell good side up into Two-Face's open palm before he sunk underwater, dead.
Three years later, when Bane broke into Arkham Asylum's property locker to get Mr. Freeze's suit, Two-Face's unique costume was glimpsed hanging on a shelf, but it was unclear if that meant that he had survived his fall and was captured or if it was simply a costume that he left behind during his last escape.
Two-Face started out as Harvey Dent, Gotham City's newly-elected District Attorney and "White Knight," and friend of Bruce Wayne (Batman). The Joker, knew Batman's connection to Dent and Rachel Dawes, his fiancée; kidnapped them both and strapped them to two time bombs. Joker told Batman their locations, but gave him only enough time to save only one. Batman chose Rachel, but when he got there, he found Dent instead.
Dent got rescued (against his wishes, as he wanted his fiancée saved) and Rachel burst into flames, and died immediately in the explosion. The left half of Dent's face got burned. Angry, the former D.A. took up the name "Two-Face" and wanted revenge on those whom he believed were responsible for Rachel's death: the Joker, Gordon, and Batman. The Joker convinced Two-Face that he was just acting on impulse before he provided him with a Smith and Wesson 64 fully loaded with ammunition, to which he flipped his newly burnt coin for his life. The coin came up on the clean side, so the Joker lived. Two-Face then found Wuertz who was one of the corrupt police officers involved. The coin then landed on the burnt side and Two-Face shot and killed Wuertz. He then confronted mobster Sal Maroni who told him that Ramirez was another corrupt officer who was involved. Two-Face then flipped the coin which landed good heads for Maroni, but bad heads for the driver whom Two-Face then shot and killed, which caused the car to tumble and presumably killed Maroni as well. Finally, Two-Face then confronted Ramirez who pleaded that she needed the money for her mother who was in the hospital. The coin came up good heads and Two-Face instead knocked Ramirez unconscious. Two-Face then captured Gordon's wife, daughter and son, and called Gordon to have him meet him "where his (Two-Face) family died" (the building where Rachel died).
Two-Face met Gordon there, where he planned to judge Gordon's son. At the time Gordon was trying to risk his life after unsuccessfully pleading for his family's lives, Batman showed up fast and joined Gordon in asking Two-Face to spare Gordon and his family. Having been manipulated by the Joker, Two-Face's hatred for the Joker is gone and instead blames Gordon. Batman asserted that Two-Face should point the gun only at those who were responsible. Agreeing, Two-Face promptly shot Batman through the stomach when the coin landed on bad heads. Then, assuming this has killed Batman, he spares himself when the coin came up on good heads. After he decided to continue judging Gordon's son, Two-Face flipped the coin. Before he could decide the fate of Gordon's son, Batman, who was wearing body armor and is unharmed, tackles Dent off the ledge of the roof to his death when breaking his neck.
Batman and Gordon agreed to cover up Dent's villainous acts by putting the blame on Batman, due to fear of the public losing hope if they found out what happened. Dent's death was used to create a new law dubbed the "Dent Act," whereby anyone with criminal affiliations would be convicted without trial or parole.
Only archive footage and a photograph of Dent is seen. When Bane found out about the truth about Dent, he used it in his crusade against Gotham. After the battles were over, the Dent Act was eliminated and all of Dent's other accolades were retracted.