Robert Downey Jr.

Jeffrey Mayer/WireImage

It seems like perfect casting now, but Robert Downey Jr. had to fight tooth and nail to get the title role in “Iron Man.” In this action flick, based on the popular Marvel comic-book series, Downey plays Tony Stark, a womanizing, hard-partying billionaire who transforms himself into a superhero. Downey, 43, has changed his life for the better after well-publicized stints in rehab, arrests and jail time. Having lost none of his quick wit and humor, Downey recently sat down with myLifetime.com to talk about cleaning up his act and why the Iron Man movie role has changed his life.

Why did you decide to do a superhero movie at this point in your career, when most of these superhero roles go to younger actors?

This one turned out pretty well. We worked our asses off and took it real seriously … There’s a sense that you’re driving to sustain a process that’s really demanding, and the product of that is you challenge yourself more. You see if you can still get in shape when you’re [my age]. I was 41 when I was cast … I’m 43 now, and it seems like this just happened a second ago. Once you’re up in your lower-to-mid-forties, it starts clicking.

What was the turning point when the filmmakers changed their minds and you were cast as Iron Man?

I did a screen test, and historically when I screen-test, I get the part.

You did a lot of improv in “Iron Man.” How does that affect your thoughts on creative control and improv in future “Iron Man” movies?

I think we’ll start off with a really airtight story and make a little more complex, and delve more deeply. We talk about the conflict and the responsibility of essentially being the destroyer of worlds and having this imaginably awesome power — beef everything up so we can have a strong foundation and then we can just play all day. Because that [the improvisation] is what I noticed the audience is responding more than anything. Luckily, we put up some good post [production], and the story tracks well from beginning to end. I tend to head due north on that stuff [improve]. I’m not like, “Dude, I’m going to do my thing.” … I think you have to do it a certain way. You can’t just start tripping off this way because you think you’re a jazz drummer. It’s still all going toward something that still has to work.

How much of a say do you have with Marvel Studios in getting Jon Favreau to direct the next “Iron Man” movies?

I would never, ever take another step in the franchise without him.

Do you feel any pressure already about how well the “Iron Man” sequels will do at the box office?

Oftentimes, the second [movie in a series] is the better one. Interestingly enough, if you look at “Batman Begins” and “The Dark Knight,” and you take completely juxtaposed sensibilities, it’s pretty much the same deal. Theirs [Batman movies] is very dark and complex, and ours is a very simple-origin story and very light.

How does your career resurgence feel now that you’ve come so far in your recovery from drug addiction?

It feels pretty sweet … I haven’t changed that much. I just started acting in accordance to … the right action. It’s not that big of a deal, because people confuse [stardom] with something … I’m one of those people too. I’m very much an attendee at the Roman Colosseum [of celebrity watching]: “Give me some blood. Release the hounds.”

What are your thoughts on your movies “Zodiac” and “Kiss Kiss, Bang Bang,” which were critically acclaimed but they didn’t do that well at the box office?

I know that [“Zodiac” director David] Fincher is a genius. There was another “Zodiac” movie, and sometimes there are bleed-throughs. Then we’re also talking about where boy meets world and producer meets market and this and that. I just don’t think that Warner Bros. felt that they were going to make their $12 million back with [“Kiss Kiss, Bang Bang”] … Things work the way they work in predictable ways. That’s why people can tell you two weeks before the movie comes out that you might as well not even promote it because nobody cares. Now, if they can only say that before you started shooting or production, they might save themselves millions of dollars a year.

Has your teenage son, Indio, seen any of your movies?

[He says jokingly] Sometimes I’ll force-feed him my classics.

Tell us about Tony Stark from “Iron Man” making a cameo in “The Incredible Hulk” movie.

Kevin Feige [Marvel Studios President of Production] called me and I said “Yes.” [Downey then jokes about the product placement in “Iron Man”]: I would also like to say “Bulgari” and say “Burger King” three times, and of course I’d like to stamp “Audi” on my forehead.

What’s the attraction to playing a flawed hero?

I think the attraction is there’s instant empathy. For me, as a movie lover, I instantly empathize with people who are people. I don’t understand [a superhero] who comes from another planet and never has a negative thought. It’s an interesting metaphor for life.

Do you think you’ve started a trend of middle-aged men playing more superheroes in the movies?

Sometimes the way these things pan is that you think you’re following a trend but you’re creating a trend, and then people follow the trend that you created. [Some people say that] it’s all just luck. I’m more of the kind [who believes that] you make your luck … It’s been a lovefest talking to journalists about “Iron Man.” But then I’m sure there are people seeing this film and saying that we’re American capitalist pigs … There’s always a black eye in the white fish. I’m not naïve anymore.