Saw is a 2004 horror film and the first installment of the Saw film series. It was directed by James Wan and co-written by Wan and Leigh Whannell. It was filmed in only 18 days and first shown at the Sundance Film Festival in January 2004. It saw an international release later that year on October 29. The movie spawned a series of sequels: Saw II, Saw III, and Saw IV.