Iron Man is the character that started it all for the Marvel Cinematic Universe (MCU). Marvel Studios introduced Tony Stark to the big screen in 2008. Since then, things took off. Big time. In 2019, Marvel’s Avengers: Endgame became the most successful film in history with a box office haul of $2.798 billion.

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The film provided a fitting conclusion to several MCU superheroes, including Robert Downey, Jr.’s Iron Man. And as you binge-watch the MCU films, we thought it would also be fun to go over what Downey and other actors have said about working on the Iron Man films.

10 Robert Downey, Jr. Nearly Passed Out During His Audition

Robert Downey Jr

Downey had a good reason to be nervous. Aside from that, Marvel wasn’t exactly sold on Downey at first because of his troubled history, although director and co-star Jon Favreau advocated for him. Nonetheless, Downey was determined to win them over. “I prepared for the screen test so feverishly that I literally made it impossible for anybody to do a better job,” the actor told Deadline. “At a certain point during the screen test I was so overwhelmed with anxiety about the opportunity that I almost passed out.”

9 Samuel Jackson's Iron Man Cameo Didn’t Take Long To Film

Samuel Jackson

In the first film, Jackson made his first appearance as SHIELD’s Nick Fury during the post-credit scenes. Filming Jackson’s scene was done in total secrecy with the help of a skeleton crew. And according to the veteran actor, their filming was quite efficient since he didn’t need much help with hair and makeup. “I was there maybe an hour and a half,” Jackson explained while speaking with Vanity Fair, according to Cinemablend. “Because I think at that time, I had my own mustache and goatee.”

8 Gwyneth Paltrow Had To Lose Weight For The First Film

Gwyneth Paltrow

Around the time that Marvel Studios was preparing to go into production for Iron Man, Paltrow had just given birth. Because of this, Paltrow knew she had to get in better shape before appearing on camera. “I did have to work out,” Paltrow told Cinema. “I shot the film not too long after giving birth so I had to lose about 15 baby-weight pounds.” The Oscar-winning actress added, “Let's just say I had to hit the treadmill pretty hard!” Paltrow’s Pepper Potts also went on to appear in the MCU’s other films, including Avengers: Endgame.

7 Jeff Bridges Helped Rewrite The Script For The First Film

As it turns out, they ran into some complications while on the set of Iron Man, particularly when it came to the script. To make things right, Bridges, who portrayed the villain Obadiah Stane, worked with Downey and Favreau on some rewrites. “We [director Jon Favreau and actor Robert Downey Jr.] read the script and it wasn't really right, you know?” Bridges explained while speaking on The Hollywood Reporter’s Actor Roundtable. “We had two weeks' rehearsal and we basically rewrote the script.” Fortunately, things turned out well in the end. Iron Man even charted a path for the MCU.

6 Scarlett Johansson Said She Got Cast Five Weeks Before Filming

Scarlett Johansson

Johansson’s Black Widow joined the MCU in Iron Man 2. At first, her character hid her true identity from Tony Stark but it became clear who she was after helping take out some bad guys.

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Apparently, Johansson didn’t have much time to prepare for the physical rigors of her role the first time around. “It was grueling,” the actress told Vanity Fair, according to Cinemablend. “I found out that I had got the role five weeks before we started shooting.” Since then, Johansson’s time in the MCU has included more action and stunts.

5 Don Cheadle Worked With Military Personnel On Iron Man 2

Don Cheadle

After Terrence Howard left the MCU, Cheadle took over the role of James ‘Rhodey’ Rhodes in the second Iron Man film. And since his character is a military man, he also consulted with uniformed personnel to portray the role properly. However, the actor noted that this made things “tedious.” “They’d be like ‘Your hat needs to be like this’ and I’d say ‘You know, we are making a movie’ and they’d say ‘Yeah, but your hat needs to be slightly this way,’” Cheadle told Get Frank. “I’ll try to adhere to the tradition, but by the same token just relax.”

4 Jon Favreau Had To ‘Chase Mickey (Rourke) Down’ For Iron Man 2

Jon Favreau

Both Favreau and Downey were determined to convince Rourke to portray the villain Ivan Vanko in Iron Man 2. Favreau told Wired, “I had to chase Mickey down because he wasn't sure he wanted to do it but Robert actually badgered Mickey every step of the way during the awards tour for Tropic Thunder.”

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And when he chased after him, Favreau made sure that he was prepared. That’s helped seal the deal. Favreau explained, “I had drawings made up of Mickey with the tattoos and the whole deal, and the role started to captivate him.”

3 Mickey Rourke Fought To Give His Character Layers

Mickey Rourke

From the beginning, Rourke was determined to give his Russian character more depth. “I explained to Justin Theroux, to the writer, and to [Jon] Favreau that I wanted to bring some other layers and colors, not just make this Russian a complete murderous revenging bad guy,” Rourke told Syfy Wire. “And they allowed me to do that.” However, these scenes he worked hard on were eventually discarded from the final cut. He lamented, “Favreau didn't call the shots. I wish he would have.”

2 Sam Rockwell Did ‘Very Little’ Improv On Iron Man 2

Sam Rockwell

Rockwell was among the other actors considered for Tony Stark. Although he didn’t get the role, it seems Favreau kept him in mind and the actor eventually landed the role of villain Justin Hammer in Iron Man 2. While working on the film, Rockwell revealed that he didn’t really do much improv even he considers himself a “pretty good improviser.” “I did very little improvisation, actually,” he told Daily Titan, “I mean, I’m a pretty good improviser, but I’m not a writer, so I like to have some structure…"

1 Ben Kingsley Drew Marvel’s Interest After Starring In Sexy Beast

Ben Kingsley

It was Iron Man 3 director and co-writer Shane Black who reached out to Kingsley after seeing his work on the thriller. Black was also impressed by how Kingsley discussed his character during a Q&A session following a screening of the film. “He wrote me a wonderful letter when he sent the script over,” Kingsley told Bring Me the News. “He told me he was at a screening of 'Sexy Beast,' stayed for the Q&A, and was very taken by the way I spoke about the character.”

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