NICOLE KIDMAN, movie star, Oscar winner and red-carpet regular, recently played a cow. Talk about your glamour roles.


The performance was for an enactment of “Jack and the Beanstalk,” which took place in her Nashville home as she was putting her 4-year-old daughter, Sunday, to bed. She also impersonated the fairy tale’s stem-climbing hero while her husband, the country singer Keith Urban, played the magic beans. “I’m like, ‘I can’t read this book again for the hundredth time,’ so I said, ‘We’re going to do it!’ ” Ms. Kidman, 45, said. (The couple also has a 19-month-old daughter, Faith, and Ms. Kidman has a daughter, Isabella, 19, and a son, Connor, 17, from her marriage to Tom Cruise.)


“Sunday sat on her bed and watched us. She was into it,” she said. Then she laughed. “Well, she didn’t tell us to stop.”


After nearly 30 years of making movies, no one is telling Ms. Kidman to stop taking on roles that challenge both her and what moviegoers think they know about her. Over a cappuccino at a Manhattan hotel last month she discussed her career and her latest unlikely role: as a Southern floozy in the intentionally pulpy drama “The Paperboy,” opening Oct. 5. Directed by the maker of “Precious,” Lee Daniels, the film earned both cheers and jeers for its audacity when it was shown at the Cannes Film Festival in May.


Ms. Kidman, an elegant blonde, is strikingly tall (she’s nearly 5 foot 11) and looked even taller in a chic black pantsuit. She spoke precisely but with an easy sense of humor. “You can ask me pretty much anything,” she volunteered. “There’ll be things I’ll go, ‘That feels a little too personal.’ But most things I don’t have a fear of being asked about.”


She said her career was founded on a drive to get inside the characters she plays. When she was younger, acting was about escaping her own insecurities by becoming someone else. Now, she said, “it’s the desire to study the human condition, the desire for collaboration, to learn and absorb, and to lead a well-examined life.”


Asked to name a role model for the next decade or two of her career, she instantly picked the French actress Isabelle Huppert. “I love the danger in her career,” Ms. Kidman said.


The director Baz Luhrmann, her friend, fellow Aussie and two-time collaborator (“Moulin Rouge!” and “Australia”), said that Ms. Kidman was a rare breed. “Nicole is a serious actor and an iconic movie star,” he wrote in an e-mail. “This combination doesn’t come along all that often.” Off screen, he said, “she can be fantastically down to earth, straight to the point, and a whole lot of fun, with a particularly Aussie sense of humor that doesn’t take itself too seriously.”


Another close friend, the actress Naomi Watts, praised Ms. Kidman’s way of navigating between commercial and independent films. “I think Nic has a wild streak in her and a very practical streak, and she manages to balance both very well, and that’s evident in her work,” Ms. Watts said in a phone interview. “She’s a fascinating and complicated woman full of contradictions, and that’s what makes her work so deep and interesting.”


Put “The Paperboy” in the wild streak column. Based on the 1995 novel by Pete Dexter, the movie features Ms. Kidman as a seemingly hot-to-trot woman named Charlotte, a resident of a small town in Florida in 1969. She writes romantic letters to prison inmates and cavorts about in derrière-hugging gold lamé pants, tight tops and straightened, teased blond hair. “I think straight hair gives me class,” Charlotte mistakenly observes.


Ms. Kidman’s risqué “Paperboy” scenes include a steamy jailhouse make-out session, sans physical contact, with Charlotte’s fiancé, a condemned murderer (played by John Cusack), and an already much-discussed beach scene in which she urinates on a worshipful young man (Zac Efron) in an effort to counteract his jellyfish stings. (In a line likely to become an instant camp classic, Charlotte, in shooing away other female, would-be Good Samaritans, proclaims that if anyone is going to urinate on the young man, “it’s gonna be me.”)


“I wanted something raw, and I wanted to work with a director who was going to access something different in me,” Ms. Kidman said of taking the part. “The script was really strong, so I was grateful to get the role.” Mr. Daniels, who had directed only “Precious” and “Shadowboxer” (2005) before “The Paperboy,” said that Ms. Kidman’s formidable résumé had him feeling intimidated initially. (Besides an Academy Award for her role as Virginia Woolf in “The Hours” from 2002, she has earned two more Oscar nominations and worked in nearly 40 films). But “she said, ‘Lee, if you’re going to direct me, you’ve got to understand that I’m just a plain working girl,’ ” he said. “And she was.”


On the first day of shooting — Mr. Daniels doesn’t believe in rehearsals — he had Ms. Kidman and Mr. Efron jump straight into the jellyfish scene. “You just go for it,” she said. “I think we did three takes, but it felt like a hundred.”


Mr. Efron said he admired Ms. Kidman’s willingness to go full throttle in that scene — she slapped him so hard trying to revive him that she apologized afterward for hurting him — and the ones that followed. As a young actor he found it inspiring and instructive to see her “go unabashedly into a part like this and just let go,” he recalled. “She’s so unafraid. There are no walls up.”