Kelly C looking perf for WSJ Magazine

Emilia Clarke, the Breakthrough Actress on 'Game of Thrones'

IF YOU'RE GOING TO WORK with dragons, once in a while you're going to get burned. Emilia Clarke found this out not too long ago in London while on break from filming the culture-conquering HBO series Game of Thrones. On the show, Clarke plays Daenerys "Dany" Targaryen, an exiled royal trying to win back her place on the throne, and the steel-willed mother of a trio of fire-belching beasts. She's one of the toughest television matriarchs since Carmela Soprano, and it's a character (and a performance) that demands respect. But on this particular night, there was this one guy.

"It was his birthday, and he was drunk," the 26-year-old actress says. "And he said, 'Please, Mother of Dragons, sing me "Happy Birthday." ' " After Clarke obliged, the tipsy stranger offered an impromptu critique of her Thrones work: 'You're doing it all wrong, you know? You're f—kin' it up,' " Clarke recounts, mimicking the carouser's gruff-bloke tone, before breaking out in a laugh. "I kind of wanted to pursue him and ask for notes: 'What exactly did you mean?' " she says. "But the reality of taking a book and turning it into a television series is that you're dealing with people's imaginations. It's impossible to please everyone."

That may be true, but during Clarke's three-year stint on the fantasy series—adapted from George R.R. Martin's gargantuan-size novels—she's done a good job of keeping Thrones-watchers happy: Last year, Clarke was the first female cast member (and the second ever, after Peter Dinklage ) to be nominated for an Emmy, and by the time the show kicks off its fourth season this spring, Dany will have earned her place as one of Thrones's best-loved figures, commemorated on everything from Tumblr-page .GIFs to homemade Etsy pillows.

Still, on this mid-fall afternoon in Los Angeles, as Clarke sits in an upscale yet unpretentious West Hollywood hotel café, no one seems to recognize her. In fact, despite the occasional run-in with English riff-raff, Clarke is seldom spotted in public, in part because she bears little resemblance to her on-screen warrior-queen alter ego: Whereas her Thrones persona is known for her golden-white hair and sand-strewn costumes, Clarke is a brunette and dressed today in cream-colored jeans and a sleeveless white-tufted Topshop sweater.

But the biggest difference between Clarke and the character that's made her famous is that, unlike the long-suffering, oft-forlorn Dany—who had to eat a horse heart, watch her lover die and tame a horde of desert brutes, all in the first season—Clarke herself is a bit of a goof. A very dignified goof, mind you, but a goof nonetheless. After all, this is a woman who sealed the deal at her final Thrones callback by busting out her dance moves in front of HBO executives. "She's effing funny," say Thrones showrunners David Benioff and D.B. Weiss in a jointly composed e-mail. "Does that mean we've written hilarious scenes for her? No. But someone should."

Clarke was barely out of drama school when she landed the job on Thrones. At the time, most of her experience had been on the stage, and her on-screen experience consisted of an episode of a British soap and a Syfy network movie called Triassic Attack. Playing Dany, who goes from timid naïf to self-assured survivor, was daunting, especially given that Martin's fans would scrutinize her every move. "I spent season one just hoping I was doing it right," she says. Eventually, she realized that she and her character had more in common than she could have guessed: Dany's an untested unknown who's been kicked into a vicious world and tasked with winning over hordes of doubting savages. What young TV actress couldn't relate to that?

CLARKE GREW UP in Oxfordshire, England, about an hour outside London, where her father worked as a theatrical sound designer. When she was still a toddler, her parents took her to see a production of Show Boat; she sat in quiet awe for the entire performance. "I think somewhere in my parents' minds, they thought, Ah, we'll just keep taking her to shows. She'll be quiet!" Clarke remembers.

She also accompanied her father to many of his jobs, and the older she got, the more intrigued she became by the sight of an empty theater. Clarke would find herself running around barren stages, imagining how they'd soon be transformed. "It's a kind of magic," she says now. "I became fascinated with what it was like to fill that space—not just with people, but with a performance. And with the way you're all creating something together."

After she announced her intention to become an actress, her father took a 10-year-old Clarke to an open audition for a show on London's West End. But they were unaware that she'd be required to both act and perform a song, and when the producers called upon her to sing, she improvised. "I was learning a folk song in school about a donkey, so I decided to sing that," she says. "They said, 'Do you know anything more current?' I then gave them my best rendition of the Spice Girls, complete with dance moves—that's where my musical career ended. It made me realize that I wasn't quite ready. I think my parents were trying to give me a healthy dose of realism early on."

Clarke spent her teens at a boarding school in Oxford, with the sole goal of getting into the esteemed Royal Academy of Dramatic Art—which promptly rejected her. Chagrined, she traveled abroad before returning to the U.K. and applying to every school she could, including the infamous Drama Centre London, whose alumni include Michael Fassbender and Colin Firth, and whose nickname is the Trauma Center. There, she was taught to drill deeply into her characters, and to prepare for the communal creativity—and constant rejection—of life in the theater. "The training definitely breaks you down, in a way that's fundamentally good," Clarke says. "It makes you humble to the work. You realize you are just a part of the thing that you're creating."

"She didn't find it a breeze at all," recalls Annie Tyson, one of her former instructors. "She was challenged, and at times she found it tough, but she had courage and determination. What emerged was an actress of imagination and real instinct."

One of Clarke's toughest days came during her third and final year at the school—a time when professional agents come to the school and seek out new talent. She'd been cast in Hamlet as Rosie—a female Rosencrantz—and as an audience of professionals watched in judgment, Clarke attempted to turn the character into a comedic foil. "It failed miserably," she says with a laugh. "There just isn't space for that in Hamlet, apparently. That might've been one of the worst days. But every horrible day just made me want it even more."

She looks lovely imo, and the interview is also great.