Sam "Ace" Rothstein (Robert De Niro), the consummate bookie who could change the odds merely by placing a bet, has come up through the ranks of the Midwestern mob to be picked by the bosses to front their entree into Vegas. In charge of four casinos, he insures that the money keeps coming in and looks the other way as the skim flows out the back, while keeping a canny eye on the quick hands of every cheat, hustler and blackjack dealer in the place. Ace lives and breathes the odds. He eventually doubles the mob's take and finally changes the very rules of how the casinos are run. Now he is ruler and high priest of all he surveys in his magic kingdom.
But Ace can't control the odds when it comes to Ginger McKenna (Sharon Stone), the chip-hustling vamp who charms him and becomes his wife. His infatuation with this glamorous denizen of the gambling room floor turns to obsession as she rises with him to the upper crust of society, then turns to the bottle and pill box for consolation in her gilded cage. Though she has broken through an icy protective layer and found her way into Ace's heart, as the story progresses, his love for Ginger becomes tainted by neurotic impulses and insidious possessiveness. This behavior portends Ace's impending downfall as he falls victim to the sin of pride.