Theron reveals monstrously funny side in 'Adult'

But all the while, there were hints in her filmography of comedic leanings. In 2005, she had a memorable arc on "Arrested Development" as the love interest of Jason Bateman's character. Her character was mentally disabled, but the joke was on those around her, who didn't notice because of her British accent.

The opportunity arose when "Monster" director Patty Jenkins directed an episode of the series, and Theron asked her to relay to creator Mitch Hurwitz her pleading to be on the show. She calls the experience a "great, great learning experience" in how comedy needn't be played for comedy, but rather portrayed realistically.

Theron also appeared on an early episode of Zach Galifianakis' faux-interview Web series "Between Two Ferns," as revered of a comedy calling-card as there is. On it, Theron flirted with Galifianakis before pulling the rug out from him, cackling at the idea of her being attracted to a "fat garden gnome."

"The bizarre thing is that I've always had kind of a sick, twisted sense of humor," says Theron. "But my work, for some reason, has always veered to the dramatic stuff. I think that's because I've never really been that driven by genre, but I find that I want to play people that feel real. I do think in comedy it's harder to find non-caricatures. I always said that I would love to do something like that kind of comedy that the Coen brothers do, that more character study stuff. And that stuff is hard to come by, and I feel like my career was setting itself up to be another thing."

The comedian-actor Patton Oswalt, who plays an old high school acquaintance of Mavis' who turns into a drinking buddy in "Young Adult," said at the Gotham Awards that Theron "has the kind of humor that someone who looks like me has."

The two found an unlikely chemistry in "Young Adult" right from the start. Before ever meeting, they did a table read in Reitman's dining room and immediately connected.

"I realized I was going to be working with a really great actor," says Oswalt. "It made me work even harder so that I could be on her playing field. She is so instinctual and already ready to go every shot."

Whether it's "Monster" or "Hancock" or "Young Adult," Theron typically commits fully to a character. Asked how she manages that, she doesn't miss a beat: "Alcohol."

But thinking a little more about it, she says that ballet instilled in her a relish for performance. Though she acknowledges she's not a trained actor, she says she learned from other actors as her career unfolded.

"It was amazing to watch Al Pacino at 3 in the morning and suck ... and then be brilliant," says Theron, recalling "The Devil's Advocate." ''It was one of the greatest teachings that I could have been given. He taught me that in order to be great, you have to be willing to fall on your face. You don't get to that place unless you go balls out."