9. Iron Man
Batman V Superman: Dawn Of Justice wasn't the only superhero universe-launching movie to start production without a finished script. Iron Man had its release date set before the film went into production. Part of the problem was that dozens of screenwriters passed on writing the film because Iron Man wasn't considered an A-list comic book superhero at the time. Though the script has four credited screenwriters, director John Favreau and star Robert Downey, Jr. weren't satisfied with the screenplay when they began shooting the film. Producers were more focused on the movies action and special effects sequences than they were on the character moments, which gave Favreau lots of freedom in that area. Many lines in the film were improvised, and Downey, Jr. actually came up with significant portions of Tony Stark's dialogue, including many of his lighthearted quips. Star Jeff Bridges actually credits the lack of a finished script for why the film turned out to be such a hit. In an interview with
InContention, he called Iron Man a "$200 million student film" and likened it to a musical group jamming. The end result was a huge success - not only was Iron Man praised for its humour, but it also became a huge box office hit that launched the multi-billion dollar Marvel Cinematic Universe.