Bad Influence is a 1990 American psychological thriller film directed by Curtis Hanson starring Rob Lowe and James Spader. In this noirish film, Spader plays a yuppie who meets a mysterious stranger (Lowe) who encourages him to explore his dark side. Bad Influence was the first original screenplay for which David Koepp received a sole screenplay credit. The film's villain is loosely based on a real person, a nomadic surfer who befriended executive producer Morrie Eisenman.