The story of the rise and fall of three friends in 1970s-era Las Vegas: Mafia-connected casino operator Sam "Ace" Rothstein, Mafia enforcer Nicky Santoro, and hustler Ginger McKenna. As the opening credits say, the film is "adapted from a true story". The source material is Pileggi's nonfiction biography of Frank "Lefty" Rosenthal, and most of the characters in the film are based on real people.