The people behind “The Fault in Our Stars” take great pains to make it clear that this is not going to be that kind of movie. We are warned about the clichés of the cancer film, and how this is definitely not that.

I can’t say this movie really avoids all those conventions, but it creates enough unusual detours to justify its existence. Based on a bestselling novel by John Green, the film takes a couple of ailing teenagers and puts them in an offbeat love story.

Hazel Grace Lancaster is 17 and an unlikely survivor of an aggressive form of cancer. She’s on an experimental drug that has extended her life — for how long, nobody knows — but also makes it difficult for her to breathe without her oxygen machine.

At a survivor group, she meets 18-year-old Augustus Waters, who lost a leg to cancer but is otherwise bright-eyed and bushy-tailed. The romance that follows isn’t too ground-breaking, but setting it against some necessary conversations about what death means and what life is all about gives the story an undeniable poignancy.

There’s also a subplot about Hazel’s devotion to a cult novel she adores. She and Augustus will get the chance to travel to Amsterdam to meet the reclusive author (Willem Dafoe) of the book.

The fact that this trip doesn’t turn out the way anybody planned is part of the oddball rhythm of the film. Yes, there are a few too many bittersweet pop anthems on the soundtrack, and a few too many teen-angst moments, but mostly these are outweighed by a goodly serving of quirk.

Hazel and Augustus are played by Shailene Woodley and Ansel Elgort, respectively. They previously played sister and brother in “Divergent,” and they’re both pleasant performers — even if he seems too goofy to romance her observant, alert skeptic.

Laura Dern and Sam Trammell play Hazel’s parents, and Nat Wolff is fun as a teenager whose eyesight loss is, to say the least, played a bit lightly.

Director Josh Boone doesn’t skim over any of this; at 125 minutes, the movie takes time to explore the kinds of questions teenagers might have in a messed-up situation like this.

I didn’t believe all those scenes, but quite a few of them clicked. Along with its credible stars, that’s enough to predict that “Fault” is going to find its target audience, big time.

“The Fault in Our Stars” (3 stars)

A better-than-average teen tearjerker, about two cancer patients (Shailene Woodley and Ansel Elgort) and their growing relationship. The film, adapted from John Green’s novel, has just enough attitude and quirk to distinguish it from the usual run.

Rating: PG-13 for language, subject matter

Opens: Friday at Alderwood Mall, Cinebarre Mountlake Terrace, Everett Stadium, Galaxy Monroe, Marysville, Stanwood, Meridian, Oak Tree, Woodinville, Cascade Mall.