Rumer Willis worked on 'Sorority Row' because she thought it was "intelligent".

The 21-year-old actress — the daughter of former Hollywood couple Bruce Willis and Demi Moore — accepted the role as geeky sorority girl Ellie in the teen horror movie because she was in awe of the "smart" storyline.

She said: "When I read it, it was a really smart and intelligent horror movie. And it was more about the characters, rather than the plot driving it. And just people happening to be there. I really liked the fact that it was kind of female-driven. And the writing was so funny. You can definitely tell the comedy when you're reading it. But I honestly had no idea it was going to be as funny as it was until I saw it."

Despite the entertaining scenes, Rumer was left exhausted from the films more emotional moments.

She explained to Dark Horizon: "It's definitely emotionally and physically draining after you're doing it for a couple hours. But it makes it easier, when you're in the environment — where we were, at least, it was freezing cold. All of the girls, we were really kind of just bringing our A-game. So I think that really helps, when you have everyone who's kind of ready to work as hard as they can, and do that. That made it easier. But yeah, of course, it's definitely draining."