The fear walking into "21 & Over" was that it would mimic one of this decade's most inexcusably mean-spirited, offensively vile so-called comedies, 2012's celebration-of-depravity "Project X." Instead—and thankfully—it comes closer to reminding of a lesser, college-set variation on 2007's "Superbad," a bawdy teen comedy that sneakily hid its warm-hearted story of male friendship behind a whole lot of R-rated hijinks. Making their directorial debuts, Jon Lucas and Scott Moore (the writers of 2009's "The Hangover") try to recreate that formula, but only succeed on random, too-sparse occasions. There is some immature amusement to be had by "21 & Over," the occasional clever line of dialogue or quirky situation, but then there's the majority of time spent wallowing in stereotypes, mixed messaging, and overbearing racial insensitivity. When it tries to go all gooey, bringing guns and even the topic of suicide into the discussion, it comes off as disingenuous and manipulative.

It's Jeff Chang's (Justin Chon) 21st birthday, and his biggest plan for the evening is to get to sleep early so he'll be well-rested for an important 8 a.m. interview his father (Francois Chau) has set up for him. Out to bulldoze all that are his two old high school friends, uncouth, directionless party animal Miller (Miles Teller) and more responsible, career-minded Casey (Skylar Astin). Jeff can only protest for so long, then, before he knows it, he's too drunk to care. A night of bar-hopping gets wilder and crazier at every turn, as Miller and Casey set off to get a passed-out Jeff home and sobered up by the fresh light of day. In the meantime, Casey falls for Jeff's classmate, vivacious sorority girl Nicole (Sarah Wright), while he and Miller begin to come to the realization that their care-free days of youth may be numbered.

"21 & Over" is nothing if not loud and proud about its bad taste and raunchy humor, opening with Miller and Casey walking across a college campus wearing nothing but a tube sock hanging from their penises, then segueing into a conversation about having sex with each other's underage sisters. By the time Miller greets the Asian Jeff Chang at his front door by calling him a "yellow bastard," it's safe to say political-correctness has taken the day off. That's fine to a point, but first there has to be a point beyond shock value, and too frequently writer-directors Jon Lucas and Scott Moore don't seem to have one. As for the trio's all-night exploits, the film's episodic nature helps matters by switching up a variety of situations every few minutes and creating different jams for the guys to get out of. There's an admittedly funny scene where their search for Nicole leads them accidentally to a Latina sorority house. Less amusing: a scuffle with a gun and a buffalo. A slow-motion bull-riding/projectile-vomiting gag is both appalling and yet beautifully shot like some sort of ballet. As for the drunken consuming of a tampon, it's a sight that one probably could live without.

The central cast members are all talented up-and-comers, asked to act below their normal intelligence. Miles Teller (2011's "Footloose") is the loud-mouthed, uninhibited one in the group, his Miller the kind of guy who speaks before he thinks and wants to keep the good times rolling because he's terrified of real life getting in the way. Skylar Astin (2012's "Pitch Perfect"), looking like Dane Cook's younger, less smarmy brother, is the comparatively straight-laced Casey, who already has a job lined up after college graduation and isn't so sure his path meshes any longer with Miller's. As birthday boy Jeff Chang, Justin Chon (2011's "Breaking Dawn Part 1") is given too little to do besides act passed out for the script to really sell his interpersonal crises that ultimately come to light. Nevertheless, Chon is up for anything and has solid comic timing. Finally, Sarah Wright (2008's "The House Bunny") is a radiant breath of fresh air amidst the muck, turning Nicole into a fun-loving, free-thinking young woman, as quick as she is attractive. In other words, it's easy to see why she fast becomes Casey's dream girl.

"21 & Over" is rampantly hit-or-miss, losing momentum the longer it goes and the more serious it tries to get. With an unsubtle music score spelling out how the viewer should feel, the film never quite finds the pathos it's searching for. Worse still, the final scenes seem to go against the characters' arcs, suggesting that—at least for Miller—he hasn't truly learned anything and is only half-committed to a future beyond working at a gas station. At least the soundtrack is solid throughout, with The Naked and Famous' symphonic "Young Blood" used particularly well on two separate occasions. A song, unfortunately, can only go so far. A debasing comedy of questionable morals and awkward lesson-teaching, "21 & Over" travels far too low to aim as high as it wants to.