In honor of his birthday, San Francisco banker Nicholas Van Orton, a financial genius and a coldhearted loner, receives an unusual present from his younger brother, Conrad — a gift certificate to play a unique kind of game. In nearly a nanosecond, Nicholas finds himself consumed by a dangerous set of ever-changing rules, unable to distinguish where the charade ends and reality begins.

When he finds out his longtime girlfriend is pregnant, a commitment-phobe realizes he might have to change his lifestyle for better or much, much worse.