Batman's secret identity is Bruce Wayne, an American billionaire, playboy, philanthropist, and owner of Wayne Enterprises. After witnessing the murder of his parents as a child, he swore revenge on criminals, an oath tempered by a sense of justice. Wayne trains himself both physically and intellectually and crafts a bat-inspired persona to fight crime. Batman operates in the fictional Gotham City, with assistance from various supporting characters, including his butler Alfred, police commissioner Jim Gordon, and vigilante allies such as Robin. Unlike most superheroes, Batman does not possess any superpowers; rather, he relies on his genius intellect, physical prowess, martial arts abilities, detective skills, science and technology, vast wealth, provocation of fear and intimidation, and an indomitable will. A large assortment of villains make up Batman's rogues gallery, including his archenemy the Joker.