Once Harvey Dent, District Attorney of Gotham City and an ally of Batman, he goes insane and becomes the crime boss Two-Face after the left half of his face is hideously disfigured when acid is thrown in his face during a trial; he chooses to bring about good or evil based upon the outcome of a coin flip. Originally, Two-Face was two of many gimmick-focused comic book villains, plotting crimes based around the number two, such as robbing Gotham Second National Bank at 2:00 on February 2. In his autobiography, Batman creator Bob Kane claims to have been inspired by Robert Louis Stevenson's Strange Case of Dr Jekyll and Mr Hyde, specifically the 1931 film Dr. Jekyll and Mr. Hyde which he saw as a boy. Kane had not read the novel when he and Bill Finger created Two-Face. Some inspiration was also derived from The Black Bat whose origin story included being splashed with acid across his face. In later years, writers have portrayed his obsession with duality and fate as the result of schizophrenia, bipolar and multiple personality disorders, and a history of child abuse. He obsessively makes all important decisions by flipping a two-headed coin, one side scratched over with an X. The modern version is established as having once been a personal friend and ally of Commissioner James Gordon and Batman.
The character has appeared in multiple Batman media forms, including video games, Batman: The Animated Series, and the Batman film series. Billy Dee Williams portrayed Harvey Dent in Batman, while Tommy Lee Jones portrayed Two-Face in Batman Forever, and Aaron Eckhart played Harvey Dent/Two-Face in The Dark Knight.