In an interview with Comic Book Resources, Rockwell has talked more about working on the movie and gone into detail about using his improvisational style during a challenging technical scene with Don Cheadle.
How do you balance those elements that the producers work on while still making Justin Hammer your version of the character?
I think that at the end of the day we're there to please them and make them happy, but they want you to do your thing. They want you to bring your originality to the role. What made Tony Stark so unique is that Robert Downey, Jr. really brought his personality to the role in a way that I've never seen in a superhero movie with the protagonist. I don't know if I've ever seen that. He's as interesting as Han Solo is. You don't usually see that. It's usually the bad guy who's more interesting than the good guy, and in this case Tony Stark is just as interesting if not more interesting than the bad guy.
Favreau briefly discussed with you the possibility of you playing Tony Stark in the first movie. In a way, is this Justin Hammer a view into a parallel world where you played that role, but maybe a sleazy b-side to Downey's Tony?
Yeah. That's kind of what they asked for. They wanted Tony's competitor to be not unlike Tony, so this was my version of that.
You had to deal with a lot of technical jargon in some scenes. How do you balance those demands even verbally while also being able to adlib and play around with your fellow actors?
Well, I had a lot of help. John Favreau and Justin Theroux helped me a lot specifically the day with the guns. They added some new guns, and I'd memorized a lot and had done a lot of research with the guns. So on the day they added the new ones, so I needed an earwig, and Justin Theroux the writer was prompting me. We're old friend, and we go way back doing theater in Williamstown. So he's very good at prompting me. So some of the adlibs are mine, and some are Justin's, and some are Favreau's coming in between takes and saying, 'Say this'.
Between the three of us, we sort of pulled that scene together. I was flailing because of the new guns they'd added. It was going south, and it came down to either being an earwig or some cue cards, and I credit Justin Theroux for feeding me a lot of the adlibs and me being agile enough to do stuff on the fly with Favreau being able to coordinate in between takes and telling us how to adjust. I think we really pulled it together, and I am pretty quick on my feet, so I was able to adjust to the two very smart men who were telling me what to do. And poor Don Cheadle is sitting there listening to all this. It was interesting. It was quite a day. It worked out, but it was hectic.
What's the relationship like with Mickey Rourke's Whiplash? How do you play off of that to make him more threatening?
Just like I think Downey's so interesting that you have to step it up as this anti-hero protagonist, it's very similar to what Terrance Stamp and Gene Hackman did in the second "Superman." It's that same dynamic. Or kind of like Peter Boyle and Gene Wilder in "Young Frankenstein." That's the comedic dynamic there.
Meanwhile, the actor has also talked to
MTV's Splash Page about how the comic books influenced his character in
Iron Man 2: