The actress has played some complex roles. But none has been as tough as this one, where she had no props to hide behind.

With all the physical and acting challenges of The Hunger Games series, you think it would be a challenging part for any actor. But for its star, Jennifer Lawrence, many things in life are more challenging — like learning to dance in front of Robert De Niro.

Lawrence's part in Silver Linings Playbook required dancing lessons with fellow actor Bradley Cooper, something that in itself can be pretty intimidating.

"I remember I thought, OK, it's going to be all right because we are holding each other and we were both very vulnerable to this choreographed dance that we were going to have to do in three weeks in front of Robert De Niro," Lawrence told Marc Malkin with E! News. "We [were] treading water together, helplessly treading water together."

Lawrence described herself as an "awful" dancer, but she said that having to learn how to dance for her part had positive side effects.

"It's a great way to get to know a person," she said. "You're instantly sweating and learning something together."

For anyone who thinks the physicality of The Hunger Games is a challenge for an actor, Lawrence explains why the vulnerability of a role like the one in Silver Linings Playbook can be much more difficult.

"If you miss a target, you still look cool because you're holding a bow and arrow," she told Malkin. "But when you mess up dancing, you just look like an idiot."

Director David O. Russell said Lawrence is on to something, but both she and Cooper were at least very willing to learn.

"They were really beginners," Russell said. "But what they lacked in skill, they made up for in passion and willingness. They had a lot of willingness.... They learned how to dance. They started out not knowing."

Silver Linings Playbook is in theaters now.

Photo courtesy of FayesVision/WENN.com