Robert Downey Jr. gain more than 20 pounds of muscle in five months to look like he "had the power to forge iron". "Iron Man" was globally released between April 30 and May 3, 2008, grossing over $585 million worldwide and receiving rave reviews which cited Downey's performance as a highlight of the film. By October 2008, Downey had agreed to appear as Iron Man in two "Iron Man" sequels, as part of the Iron Man franchise, as well as "The Avengers", featuring the superhero team that Stark joins, based on Marvel's comic book series "The Avengers". He first reprised the role in
Iron Man (2008 film) the star, the superhero is the star. The success of "X-Men" and "Spider-Man" without being star-driven pieces reassures [executives] that the film does have an upside commercially." However, in September 2006, Robert Downey, Jr. was cast in the role. Favreau chose Downey, a fan of the comic, because he felt the actor's past made him an appropriate choice for the part, explaining "The best and worst moments of Robert's life have been in the public eye. He had to find an inner balance to overcome obstacles that went far beyond his career. That's Tony Stark." Favreau faced opposition from Marvel