Prior to 2003, Wan and his friend, screenwriter Leigh Whannell, had begun writing a script for a horror film, citing their dreams and fears as inspiration for its plot. Upon completing the script, Wan and Whannell had wanted to select an excerpt from their script, later to be known as "Saw" and film it to pitch their film to studios. With the help of Charlie Clouser, who had composed the score for the film, and a few stand-in actors, Wan and Whannell shot the film with relatively no budget. Whannell also decided to star in the film as Adam Faulkner, one of the film's main protagonists.