Sam Rockwell is an actor known for taking interesting and challenging roles, such as game show host Chuck Barris in Confessions of a Dangerous Mind or the sex-addicted Victor in Choke, which likely prepared him to take on two difficult roles, that of astronaut Sam Bell in Moon, a movie that revolves entirely around Rockwell's solo performance, and rich industrialist Justin Hammer in Iron Man 2, a role Rockwell accepted "on faith" when the script arrived only one week prior to shooting.
With both movies, Rockwell is having a great time, in part due to the amount of improvising he gets to do, especially on Iron Man 2:
It's not dissimilar to other studio movies, but the thing that's different about it is [director Jon Favreau] really likes to improvise. So we get to play more on this movie than you would on a lot of studio movies.
Moon, with only Rockwell as the camera's focus, also had opportunities for improvisation:
The first [take] that you'd shoot you'd have more room for improvisation. The second one you'd have to get it within the window of time — you had a space of time for your line. I could change the ad-libs as long as they fit the same amounts of beats. You could ad-lib but you had to be very clever about it, otherwise it wouldn't work.
Still, acting alone is a challenge no matter how much freedom you have, as Rockwell discovered working on Moon:
I had a body double, and he was a young actor who I would work with sometimes. And sometimes I would work with a tennis ball, and I would act with myself. It was pretty complicated. My sense of timing came in handy. Whether that be comic timing, or like dance or something. Timing was very instrumental in making it work.
With Moon finished and released Friday in New York and L.A. before opening in other cities, Rockwell can now concentrate on Iron Man 2 and his fight scenes with Mickey Rourke:
We don't punch each other physically, but we do punch each other in other ways — it's emotional.
And this time, he won't have to do it alone.