From edgy superhero fare with the “Kick-Ass” films and fantasy drama with “Hugo,” to horror with “Carrie,” horror comedy with “Dark Shadows” and intensity with the upcoming crime thriller “The Equalizer,” there’s no question that Chloë Grace Moretz has had more variety in her roles before age 17 than most actors see in a lifetime.

But that’s the way Moretz likes it, which is why the acclaimed actress has cast yet another new mold as the lead role in the compelling new teen drama “If I Stay.” After all, Moretz, said, she’s a teenager, and teenagers like to change up things frequently.

“I think in a way I blame my teenage mind for the diversity in my roles,” Moretz told me in a recent interview. “As a teenage girl, I can’t really choose what to wear in the morning, and in the same way, I can’t really choose what my next movie is going to be. I feel that’s why my movie choices are all over the place. My emotions are changing every other month, so I think my movies change with me.”

In “If I Stay,” opening in theaters nationwide Friday, Moretz plays Mia Hall, a high school senior and gifted cellist who is on the road to musical greatness when a car crash kills her family and leaves her in a coma, clinging to life.

Through an out-of-body experience, Mia recounts pivotal moments in her life, and is reminded through the whispers of an emergency room nurse that it’s only her fight that will determine whether she lives or dies. The dilemma, however, comes with a difficult choice: If she emerges from her coma and survives, she will become an orphan yet be with the love of her life – the budding rock musician Adam (Jamie Blackley). If she dies and moves on into the light, she will reunite with her family in the afterlife, but effectively leave the people who promise to be her family in the aftermath of the tragedy.

Based on the bestselling novel of the same name by Gayle Forman, “If I Stay” also stars Mireille Enos (“The Killing”) and Joshua Leonard (“The Blair Witch Project”) as Mia’s parents, and legendary actor Stacy Keach as her grandfather.

While Mia is effectively tasked with a choice to stay or move on, one could easily argue that “If I Stay” effectively examines the idealism of  Free Will. And while Moretz agrees with that observation, she also said “If I Stay” isn’t a film isn’t necessarily a film about faith.

“The interesting thing about ‘If I Stay’ is that it’s not religion based,” Moretz explained. “We made a movie that’s a lot about the subject (of Free Will), but what was cool is that didn’t have to force feed religion down your throat with it. We leave it up to your interpretation. Its ideas are whatever you want them to be. I think it’s more interesting that way instead of telling the story from a biased point of view. It’s told from a very open-minded point of view that’s more interesting than others.”

Having been exposed to film properties with built-in audiences before — “Kick-Ass” was based on a comic book series, while “Carrie” is remake of a 1976 horror classic based on Stephen King’s classic bestseller — Moretz says she very much respects fans’ opinions when it comes to screen adaptations of beloved source material.

“Whenever I do a movie based on a novel with a very large fan base or following, it affects me,” Moretz said. “I definitely try to use the source material to help me because the readers are the true fans of it. They’re the first fans of the material.”

And with “If I Stay,” Moretz said her approach was no different.

“I’m a fan of the novel, too, so I definitely tried to do the material justice and be honest and true to the fans of it,” Moretz noted. “Without the book, we wouldn’t have the idea for the movie.”

And while some actors purposely avoid the original source material and wouldn’t even think of reaching out to the author with questions, Moretz said she had no problem talking with Forman. The interesting thing is, Moretz didn’t necessarily ask Forman about what was in the book, but about smaller specifics that author used to build her character that didn’t make the pages.

“I asked Gayle things like, ‘What is Mia’s birthday?’ and stuff like that — smaller things that I couldn’t get from the book,” Moretz recalled. “Immediately, it became a super-collaborative process between me and Gayle. A lot of her answers were like, ‘I had no idea what her birthday is. Let’s make it up together to see who she is.’ She was very collaborative in the film in the beginning, and continued to be that way. I got very lucky with that.”