During this period, Damon joined two lucrative film series—Ocean's Trilogy (2001–2007) and Bourne (2002–2016)—and produced the television series Project Greenlight (2001–2005, 2015). In the former's first installment, Steven Soderbergh's 2001 ensemble film Ocean's Eleven, which is a remake of the Rat Pack's Ocean's 11 (1960), he co-starred as thief Linus Caldwell. The role was originally meant for Mark Wahlberg, who refused it in favor of other projects. The film was successful at the box-office, grossing $450 million from a budget of $83 million. Damon, alongside Affleck and others, produced the documentary series Project Greenlight, aired on HBO and later Bravo, which helps newcomers develop their first film. The series was nominated for the Primetime Emmy Award for Outstanding Reality Program in 2002, 2004 and 2005. Damon later said that he and Affleck felt proud that the show helped launch the careers of several directors; Damon later served as the executive producer of a number of projects directed by the winners of the show.
Damon began 2002 with writing and starring in Gerry, a drama about two friends who forget to bring water and food when they go hiking in a desert. The reviews for the film were generally positive, but it was a box-office failure. He then played amnesiac assassin Jason Bourne in Doug Liman's action thriller The Bourne Identity (2002). Liman considered several actors for the role, before he finalized Damon. Damon insisted on performing many of the stunts himself, undergoing three months of extensive training in stunt work, the use of weapons, boxing, and eskrima. Damon said that before The Bourne Identity he was jobless for six months, and many of his films during that period under-performed at the box-office. He doubted on the film's financial prospects, but it proved a commercial success. Reviews for the film were also positive; Roger Ebert praised it for its ability to absorb the viewer in its "spycraft" and "Damon's ability to be focused and sincere". For his role, Entertainment Weekly named Damon among "the decade's best mixer of brawn and brains."