Transcript for Oscar Contenders: 'American Hustle'
You may not think of American hustle as an underdog. Christian bale kept turning him down. It's more than just the characters who had to hustle. Here's Chris Connelly with our series "Oscar confidential." People believe what they want to believe. The guy who made this so good that it's real to everybody. How's this for real? More than $100 million earned at the U.S. Box office. Ten academy award nominations. Including ones in each of the four acting categories. Proof that "American hustle's" appeal is no con job. He wasn't necessarily in good shape and he had this comb over that was rather elaborate. For best actor and best actress nominees Christian bale and Amy Adams. Their con artist's couple secret weapons, the way they get potential marks to fall for a scam is by first telling them no. The key to people is what they believe and what they want to believe. I think that when you say no, it creates allure and it makes people more curious. I think that can happen in relationships as well. The more people push you away, the closer you want to get to them. Can we talk business. It's that taboo. I discovered that working in films as well. When you turn something down, they keep coming back with better offers because they don't really believe you. I was there the whole time. You don't really know it. Y become somebody people can pin their dreams on. Now almost 40, bale initially turned down the chance to play Irving Rosenfeld on the movie based on the scams in the 1970s until bale's spouse stepped up for him. I said I don't have the time to do this properly. And my wife got on the phone and she said, he will talk out of everything. Just ignore him. He can do this. Thankfully she was right and I thank you very much for having sorted that out. We've got to get over on all these guy ps . Adams found herself drawn in by the vision of her character, scripper turned grifter Sidney that rus shell shared in their initial meeting. He said I want her to be the smartest person in the room. I want her to be just a survivor, and I really keyed in with that. You're going to have to decide for yourself, kit. I just laid everything on the table. Strength is so much fun to play for me. It's so much fun to be the person who doesn't care what anybody else thinks because it's just so not who I am. Bale cast aside his dark Batman silhouette, messed on his hairline and packed on some 50 pounds, thanks to the real life con man who partnered with the FBI to catch dirty politicians. I was greatly inspired seeing members of earl Wineberg. He's a charming figure who sort of waddles. I said I have to pursue, I have to ask for that man. It just became me saying I don't see how to play it without looking that way. What's the "S" stand for. For her character so different from Lois lane in the man of steal or "Her's" lonely game designer. She decided she would say yes to the des. I could only dream about these dresses they're beautiful. And no to pretty much anything beneath it. Daring to bear first urged on her by custom designer Michael Wilkinson. He was smart. There was a sort of confidence that happens because your posture has to change to keep everything in place. The idea in her mind is if men aren't paying attention to the details when they're distracted, maybe they won't ask as many questions. Adams and bale worked together before on a David Russell film "The fighter" which bale won a best supporting actor Oscar. We didn't have that many scenes together in "The fighter" but the good thing is we've been through the process with working with David. We know what to expect. The first time I worked with him, he was sending texts during a table read about his ideas about my character. I thought oh, my gosh, he hates what I'm doing when really he was just excited and coming up with ideas. 24 hours a day David is texting you. So you are really committed. You don't ever just turn it off and say -- I do. I have a kid. A lot of actors like to be very controlled, know exactly what's happening. And I'm not that kind of actor. I like it to be very spontaneous. I don't mind saying it's chaotic. I don't know if David would appreciate hearing that word used. And I think you really strike gold sometimes when you have attitude. He died this year. He saved my life many time 37s. Mine, too. During preproduction that song "Jeeps blues" would send Adams into a private reverie that Russell and her co-star Bradley cooper would witness. Did you come upon Amy Adams dancing to that duke Ellington song in your production song at one point? Yes. And there's Amy with the lights kind of off dancing like ann-margret in my office. There's things you don't think people will talk about. And then it's revealed you're doing a dance number in a production office. Each powering these American hustle Oscar nominated perform mans. And lessons from bale's real-life role M.D. Odel. You believe what you believe as you're doing it. And to be a con man, you have to have a big set of balls, you know? I would assume that's important. That's important, I guess. He said a good line of And a big set of balls. I'm Chris Connelly for "Nightline" in Los Angeles.
This transcript has been automatically generated and may not be 100% accurate.