Bridges, who can currently be seen in TV series The Old Man, reflected on the Jon Favreau-directed film in a new interview with The Independent.
“Downey was so great in that, and we had a ball making it,” the actor, who played the villainous Obadiah Stane, said.
The actor revealed that he struggled with the improvisational filmmaking process at first, and had to make “a little adjustment” to cope.
“It was kind of written day by day; we’d go into our trailers and we’d try and figure out how we’re going to do the day’s work, basically,” he said, adding: “It was very frustrating for me until I made a little adjustment in my mind, because I like to kind of know my lines and study and all.”
He continued: “I just made a little adjustment – ‘Jeff, relax man, have fun; you’re making a $200m (£177m) studio film. You know, just have fun – look at these guys you get to play with.’ So we just had a wonderful time.”
Elsewhere in the interview, Bridges opened up about his cancer diagnosis and bout with Covid.
Find The Independent’s full interview with Bridges here.