For those who don't recognize the acronym, it stands for "designated ugly fat friend" and is used in the social media world, where fast and unfriendly is always a hit.
Madison (Thorne) is popular, a shoo-in for prom queen, beautiful and, because that just isn't enough, the leader of the hit squad. Bianca (Whitman), smart, cynical and easygoing, is Madison's prime target. Wesley (Amell), the quarterback, cool, cute and Bianca's next-door neighbor, is the man in the middle, though he doesn't know it yet.
Directed by Ari Sandel, the film is slightly less edgy than the novel by Kody Keplinger, who distinguished herself by writing "The DUFF" when she was 17. Platitudes about being happy with who you are get piled onto the comedy, adapted for the screen by Josh A. Cagan.
Going in the film's favor are Whitman and Amell, excellent actors already, and very good together. Since Bianca and Wesley have known each other since they were kids, the teasing comes naturally. Until a life-changing moment at a party when Wesley introduces Bianca to the term — DUFF, as in she is one, the ugly fat friend whose very presence makes her beautiful besties look even better.
He considers it high praise, the way Jess (Skyler Samuels) and Casey (Bianca A. Santos) have become so popular. But the designation shakes Bianca to the core and, for a while, ends her friendship with Wesley and tests her bonds with Casey and Jess.
The devastating judgments are to be expected of teens, I suppose. It is what happens next that is so troubling and, sadly, just as routine. Instead of staking a claim on her individuality, Bianca slides into self-doubt. Suddenly, instead of creative or academic obsessions, she's worrying about the gap between her sense of style — overalls and flannel shirts — and her friends' designer wardrobes.
It throws her into a lot of soul-searching, which becomes the heart of the film and brings in all the ancillary characters. The best of the lot is Ken Jeong as Mr. Arthur, her favorite teacher, who gives her an assignment to write about what prom means to her. Ugh.
Jeong is so much more likable here than the screeching, profane Jeong of "The Hangover." Toned down, he is actually funnier. The excellent comic actress Allison Janney as Bianca's mother Dottie — a bitter divorcée turned motivational speaker — is left with the clichés.
As is so often the case in movies about high school girls — "Carrie," "Mean Girls," "Cinderella" — whatever besets our heroine, it will all be sorted out at the prom, the spring fling, the ball.
Whitman, who created such a believable portrait of a struggling teen in NBC's just-wrapped drama series "Parenthood," has a great deal of talent that goes unused here. As likable and funny as Whitman is — and for what it is worth, she carries the film — the repackaging of Bianca, taking her from DUFF to, sadly, puff, doesn't begin to show what the actress can do.
Her best scenes are with Amell, particularly when they are away from the high school in-crowd. Some human moments surface, though any time their conversations threaten to go deeper, the filmmakers pull back. It's as if they are the nervous ones, relying on a joke to mask their discomfort.
Meanwhile, Thorne has a go at trying to become one of those iconic girls to hate, but her attempt is a shade too one-note. Nothing close to, say, Reese Witherspoon in "Election."
Madison's weapon of choice is viral videos, because this is 2015, lest we forget. There is a great deal wrong with those videos — their seriously destructive cyberbullying streak among them — but something else as damaging is there too.
The clips designed to destroy Bianca are taken while she is undergoing a makeover with Wesley's help. Wesley's advice is played as a sweet, flirty, friend thing — i.e. good — while all the bad angles and bad language Madison and crew superimpose on the video are the awful part.
In reality, it is not that black and white. Madison is clearly wrong and diabolical, no debate. But trying to turn into someone you are not through better dressing and flirting tips from your hunky jock friend would seem to defeat the whole self-empowerment idea that the film keeps hitting at — and which rational adults keep hoping for in teen fare.
Soon all the qualities that made Bianca so likable are being repackaged in order to attract a boy. In her case, she thinks the guy of her dreams is the guitar-strumming, sensitive indie rocker Toby (Nick Eversman).
Romance, or the desire to find someone special, isn't a bad thing — if it's not the only thing. But as it stands in "DUFF," the denouement at prom has cliché written all over it.
MPAA rating: PG-13 for crude and sexual material throughout, some language and teen partying
Running time: 1 hour, 40 minutes
Playing: In general release