The Game (1997)

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

Tags: bewildered, birthday present, conspiracy thriller