Jeff Bridges has been a welcome presence in American movies for four decades, having starred in classics like The Last Picture Show and The Big Lebowski. He?s also got a few genre titles like Tron and Starman under his belt. But he hasn?t starred in a big-budget comic-book adaptation before?until now. Bridges plays the bald, meglomaniacal Obadiah Stane in director Jon Favreau?s Iron Man, functioning as both a mentor and antagonist for the title character played by Robert Downey Jr. We chatted with the veteran actor at the film?s press junket last weekend in New York City, where he spoke about getting his head shaved and getting in touch with his inner supervillain?

Did you know that you would have to shave your head and grow a beard for this film?

No. When I saw the comic book, I said, ?I get to shave my head,? because the guy is bald. I talked to Jon about this, about shaving my head, and he said, ?You don?t have to do that. We don?t have to be a prisoner to the comic book, but it?s up to you.? I got excited about it. Then all the anxiety that I had when I was a kid getting my haircut started surfacing, and then it took me a while to get it done.

What did you do to get jobs afterwards? Did you have start wearing wigs?

My hair grew back pretty damn fast. I have had several haircuts since then actually.

This is a new kind of film for you. You haven?t done this sort of superhero genre film before. What about it appealed to you?

Jon Favreau was the real appeal to me. I?ve been a big fan of his since Swingers, and the combination of Jon doing this comic-book genre film seemed so intriguing to me, I went to hear his pitch. And when he told me that Robert [Downey Jr.] was going to be Iron Man that made it all the more wonderfully odd. I thought, ?Oh God, this could be exciting, very different.? That?s what got me to the party.

Even as your character is being evil and beating Iron Man, he never stops being this father figure.

I think there are other aspects, good and evil, in all of us, with evil being self-serving. But then you get into this higher stratosphere, I suppose, with that kind of thinking. You get this psychopathic deal where Obadiah considers himself a hero. He?s the guy who?s ?I?ll be the bad guy. You can all blame me, but we both know that I put this whole thing together. What I?m doing?you can say it?s terrible, while you go out and get your burger at the fast-food chain and drive your hot cars. I?m holding the whole thing from the beginning.? He thinks of himself in those terms.

When the lines are blurred between good and evil, is there a mechanism for you to interpret that? Do you have a particular way to describe it?

I don?t approach a protagonist or antagonist differently really. I prepare for those roles in the same way. There?s a reality that each movie has or each story. You don?t want to rip that fabric. You want to stay in that, and that was one of the things that appealed to me in this movie?that it didn?t have a strong message being shoved down your throat, but it?s trickling all these themes and ideas to be discussed.

Do you think you could be back for another film or two?

Maybe, I don?t know. They haven?t asked me yet.

Did you sign up for three movies?

No. It?s all up in the air.

Can you talk about the improvisation that Jon encouraged the actors to do. How does that work with Robert when he?s doing the improvisation?

Well, we had some great writers on the set and we had a script that was constantly changing. Because there were some unusual elements that had to be approved and there was a lot of uncertainty about all that?which drove me crazy at the beginning because I could be prepared as I can, and then you read a script. What you said about people and what other people said about you, that?s how you define your character. If that?s all up for grabs and nobody?s on the same page, you start to panic. Often, we would show up for the day?s work not knowing what we were going to say that day. You would go into Jon?s trailer for a couple of hours with one of these little tape recorders and we would jam. We would play each other?s character and we would all have ideas and throw them around, and the writers would be in the room and the producers. It took me a while to get behind that. For a few weeks, I was panicking and it really rubbed my fur the wrong way. That?s not how I like to work. However, that?s the way to do it. There?s certain ways you would like, and it?s weird, but that?s how it is. It?s like you go to a ballroom, and you?re all prepared to dance the waltz, and then they just play cha-cha all the time. So, I finally got my cha-cha shoes out, and had fun playing the game that was being played. I was reminded of working with Hal Ashby, one of my favorite directors from Coming Home and Harold and Maude and all kinds of great classics. He used to drive the financiers crazy because he would do much more improvisation than this. ?You say whatever you want to say.? He had such faith in the actors that he would set some great footing. On this one, when I finally got with the program, it was kind of fun, and the fact that Jon Favreau is a wonderful actor himself and knows how different actors approach the material and he tried to give us all what we needed and was calm, and allowed the way it was to turn into this movie?. That?s because of Jon.

How?s the technology different from the days when you made Tron and Starman?

Basically, it?s the same thing. You use the same technique you use in special effects movies. You are using your imagination. If you are working with a kid and kids can only work a certain amount of hours a day, you often find yourself working to a little ?X? on a table. ?Come on Johnny, your mother loves you??you?re out of your mind. That?s basically the same trick. Now they have this motion-capture thing. We didn?t do much of that. We had to show up in tights with a bunch of electroids on them. We would be in a small green room; and everything is done in post. All of the sets, costumes, and the camera angles. That?s a whole new skill to take the imagination to another level.

Speaking of technology, there?s been some talk about ?Tron 2.0?. Have you heard about it?

Yes, I have heard about it. I have heard the same rumors. I don?t know. It would be interesting. If they had a good script, we?ll see.

Have they approached you?

No, not yet. I?ve heard the rumors! [Laughs.]