Screen teen angel

Kat DENNINGS doesn’t play your ordinary teenager. She wouldn’t know how.

As a high school senior who winds up on a romantic night out in Manhattan in “Nick & Norah’s Infinite Playlist,” she’s entirely believable but never predictable. The low-fi romantic teen comedy, which opens Friday, relies on the chemistry between its two leads for the audience to care about their late-night adventures and emotional exploration. Michael Cera, who plays Nick, has been reliably serving innocence on wry since his years on the Fox TV show “Arrested Development” and more recently in “Juno” and “Superbad.” Dennings’ Norah, in all her goofy charm and vulnerability, is his perfect match.

“The most exciting thing to me about Kat is that she seems to be totally unaffected by other people’s expectations of the way a young actress should perform in this kind of a film,” says “Nick & Norah’s” director, Peter Sollett (“Raising Victor Vargas”). “Her being liberated from that liberated the film in many ways, and certainly her character from cliche.”

That refreshing disregard for the de rigueur is just as noticeable in “The 40-Year-Old Virgin,” in which Dennings played Catherine Keener’s put-upon teenage daughter, and in “Charlie Bartlett,” as the love interest to the titular character, a high schooler and would-be therapist played by Anton Yelchin.

“She’s like everything that Molly Ringwald and Winona Ryder and Julia Roberts were, wrapped up into one amazingly talented girl,” says “Nick & Norah’s” screenwriter, Lorene Scafaria. “She’s just so natural.”

Sitting in a Burbank cafe on a recent sweltering day, Dennings hears the relayed compliment and her huge gray-blue eyes widen further. “I want to date myself!” jokes the ingenue. The 22-year-old actress provides a simple explanation why her characters never feel like your typical high schoolers: She never went to high school.

“I don’t know the way normal teenagers act,” she says.

Home-schooled

Dennings, who was born and raised outside Philadelphia, surrounded by woods and creeks and horse farms, says she was a sensitive kid who just couldn’t bear the school environment. “I kind of wanted to stay home and write and be around my trees and stuff,” she says. Preschool was a short-lived experience. “I’d cry all day and want my mom and want to go home. I know that a lot of kids have separation anxiety, but it was something else.” Her mother decided to home-school her.

There was one exception to her reclusive behavior: She wanted to act. Her father, a biochemist, and mother, a speech therapist (now a poet), were baffled. Says Dennings, “They’re like, ‘Where did you read this? Who told you about this?’ We’re in the woods, I wasn’t allowed to watch TV.” But she harangued them daily. When she was 10 years old, they finally broke down, allowing her to try it for one month.

Soon she was heading out on auditions and facing endless rejections. “And they’d say, ‘Oh, you’re too this or too that. You’re not this enough. Your teeth, your hair,” recalls Dennings, who has never conformed to Hollywood’s narrow standards of beauty. “It’s terrible. It’s the worst environment for a growing girl or person in the world.”

Still, Dennings loved every minute of it. An avid student, she finished all of her high school course work at age 14. That year, she also landed her first notable role on “Sex and the City,” as a bat mitzvah girl whose racy exploits are too much even for Samantha. A role in a pilot led to a temporary move to Los Angeles with her mother. More roles followed, the move became permanent, and her father and brother soon joined them.

So after 12 years of work, she laughs about being widely touted as a newcomer for her role as Norah. It is certainly her biggest role to date and one she recognizes as a turning point in her career. But for all that, she felt no pressure taking on one of the title characters and working full time on a 30-day shoot. Make that 30 nights, in winter, on the streets of New York. Dennings found it easier to be working constantly than to wait days for a scene and worry about how she would play it, as she had with smaller roles.

Before shooting began, she rehearsed with Cera and Sollett in Manhattan -- time spent walking around the city, visiting the film’s locations and hanging out together was just as key. Their process mirrored that of the characters, who get to know and like each other over the course of a single evening as they travel around the city in search of a secret show with their favorite band.

Norah emerged effortlessly from there. “I just was Norah for the time that we shot,” she points out. “There was no other option. I can’t really switch on and off like that. Especially when you’re in every scene.” For a while she even thought she was playing herself, until the shoot was over and she saw the distinctions more clearly. Where Norah is insecure and a bit of a pushover, Dennings has no such issues. “I don’t care what anybody thinks anymore; I only care how I feel, and my family,” she declares. “I’m fine with myself. There’s no other option if you want to be happy.”

It’s a bold enough stance for anyone. For a young actress in Hollywood, it’s a bit miraculous. Unsurprisingly, Dennings eschews celebrity. “Why would you want to not be able to leave your house without being photographed?” she asks. “I already don’t leave my house. Even premieres for my own films scare me a little bit.”

Indefatigable blogger

But again, protecting her privacy comes with an asterisk -- Dennings has been blogging about herself, at katdennings.com, since 2001. (She started because her brother was doing it.) The entries and videos cover subjects like “finding a lizard in my bathroom, and discovering a new kind of cheese that I’m obsessed with,” she says. “That is literally the exciting stuff in my life.” She takes a tip about Manchego with the gravity deserving of a clue to the Holy Grail. A recent post about the film “The House Bunny,” in which she played a sorority girl, reads: “The cuteness! It burns!”

She’ll play college students but doesn’t plan to be one. “My dad said it best: ‘You go to college to figure out what your career is going to be, and you know already,’ ” remarked Dennings.

And there’s little chance the collegiate life could match the joy she’s found already with her professional life. Dennings had so much fun on “Nick & Norah” that she wanted to take pictures to record every moment, until she remembered that those moments were actually being filmed.

“People would think that everyone’s mean and catty” in the film industry, Dennings says, “but my experience has been that this business is filled with people who probably had a hard time in high school, you know what I mean? Creative people who got the shaft. I don’t want to generalize, there are a lot of [jerks] in this business for sure, but on these sets of movies that you really love, usually you’re with like-minded people.”