By Sara Vilkomerson
August 15, 2014 at 04:00 AM EDT

Chloë Grace Moretz has played an assassin (Kick-Ass), a sheltered high schooler with telekinetic powers (Carrie), and a cellist trapped between life and death (this month’s If I Stay). But a regular teenager? Not so much. ”I was about to say Dark Shadows, but I played a werewolf in that one,” says Moretz, laughing. ”I don’t find them interesting.” Yet in Laggies, the 17-year-old star portrays a believably eye-rolling adolescent who lives with her single dad (Sam Rockwell) and befriends a woman in her late 20s fleeing her grown-up responsibilities (Keira Knightley). ”It was one of the chillest sets I’ve ever been on,” she says. ”Sometimes we filmed. Other times we were just talking.” Moretz loved the low-budget aesthetic of director Lynn Shelton (Your Sister’s Sister). She also leaped at the chance to work with Knightley, one of her screen idols. ”My brother and I were always raving to her about how obsessed we’ve always been,” she says, adding that she’s seen Pride & Prejudice roughly ”one billion times.”

Moretz doesn’t get much downtime to watch movies these days. She plays a sex-trafficking victim opposite Denzel Washington in September’s The Equalizer and soon begins shooting The 5th Wave, based on Rick Yancey’s acclaimed young-adult novel about a 16-year-old survivor of a deadly alien invasion. In real life, Moretz seems to have the inner grit to navigate a landscape that can be scarier than any dystopia: Hollywood. Take, for example, her stance on auditioning. ”Honestly? I’m not afraid of the competition,” she says. ”I’m willing to fight for anything I feel passionate about. If I think I’m the best girl for the job, I’m going to let them know it.” How does someone so young become so self-assured? ”Oh, I’m only confident when it comes to my job,” she says with a laugh. ”Put me in a room with a bunch of 15-year-olds and I don’t know how I’m going to act.”