An escalating war between new parents and the hard-partying fraternity that moves in next door is the comic crux which pushes the "Neighbors" plot forward, but the film earns its most affecting material from the relationship between a young couple struggling to not lose themselves in the face of mounting adult responsibilities. With 2008's "Forgetting Sarah Marshall," 2010's "Get Him to the Greek," and 2012's "The Five-Year Engagement," director Nicholas Stoller has retained a consistently pleasing sensibility that he carries over here, one that draws audiences in with raucous R-rated humor and then wins them over with an articulate, verifiable human component. Anyone can throw a stream of broad, raunchy jokes onto the screen and hope they stick, but if there is a real story, identifiable characters, and a beating heart behind them it can go a long way in smoothing over the occasional slack gag and rambling pacing.

Mac (Seth Rogen) and Kelly Radner (Rose Byrne) used to entertain a busy social life full of friends and carousing, but now that they have baby girl Stella to take care of they often find themselves too exhausted to make it out the front door. When the house next to them goes on the market, they cross their fingers it will be sold to the nice gay couple they see looking at the property. Instead, they get college frat Delta Psi Beta, led by BMOC Teddy Sanders (Zac Efron). Suddenly, Mac and Kelly are confronted with loud, thumping blowouts every night and absolutely no peace and quiet. In an effort to come off as cool, they introduce themselves and even offer up a joint to show how laid back they are. Teddy asks that they come to him whenever they are being too loud, but when this doesn't work and calling the cops with an anonymous noise complaint blows up in their face, the couple become the targets of a spurned frat house.

The premise of "Neighbors" opens itself to mounting mean-spiritedness, but director Nicholas Stoller and writers Andrew Jay Cohen and Brendan O'Brien never lose sight of the people behind the skirmish and their respective points of view. By paying attention to where the characters are coming from, they mostly avoid the would-be unctuousness that might have otherwise destroyed the finished outcome. Teddy hasn't yet grown up—in his last year of college, he is clinging by the nails to this self-made bubble of youthful, foolhardy abandon—but he also isn't without a conscience and a value system. He welcomes Mac and Kelly into his world, then feels wronged when they go behind his back and get the police involved. The tactics of sabotage which ensue are wrongheaded, but Mac and Kelly can give every bit as well as they receive and aren't about to let Teddy and his brothers get away with it. Their acts of retaliation, from flooding Delta Psi's basement, to convincing school dean Carol Gladstone (Lisa Kudrow) to put the students on probation, to playing sneaky mind games that pit the guys against each other, are the source of some of the biggest laughs.

Seth Rogen (2013's "This Is the End") and Rose Byrne (2013's "The Internship") are winning as Mac and Kelly precisely because they are so different from the straight-laced, stick-in-the-mud grown-ups one typically finds in these kinds of roles. Mac and Kelly have plenty of party years behind them and, in a way, envy Delta Psi's lack of restraint and obligation. They want to be lax with the fraternity, but also have a home, jobs, and a child to look out for. Together or apart, it doesn't matter; Rogen and Byrne are exceptionally skilled in their outstanding comedic timing, keen intuition, and relaxed, natural improvisational abilities. Their initial attempts to act chill while simultaneously telling Teddy and right-hand man Pete (Dave Franco) to keep it down are enormously funny, as is Kelly's unfiltered potty mouth. Beneath the humor, however, is the story of a couple who experience the first strain in their marriage and come out the other side stronger and more in love than ever. It is this element that is most memorable, bringing a little emotional maturity to frequently immature hijinks.

Zac Efron (2014's "That Awkward Moment") holds his own as Teddy, an antagonist amusing in his cutthroat schemes but not unredeemable. That he does have a nice side and a lurking fear for the future signals that he's more than just a one-note bad guy, and Efron has fun diving headfirst into his uninhibited part. Dave Franco (2013's "Now You See Me") is well-used as Pete, Teddy's more focused and together friend, though a homosexual subtext that shows up near the end proves awkward when it is treated as a throwaway punchline with no actual purpose or payoff. As wild frat member Scoonie, Christopher Mintz-Plasse (2013's "Kick Ass 2") is underused in a role that could have been portrayed by anyone, while the forever-welcome Lisa Kudrow (2010's "Easy A") brightens up her too-few scenes as by-the-book dean Carol Gladstone.

As feature-length comedies frequently tend to do, "Neighbors" loses steam in the third act, leaning more toward chaotic than clever as Mac and Kelly come to blows with Teddy after infiltrating his house. At 96 minutes, the film could have been tightened to a better, fleeter 85 minutes. What one takes away and remembers most fondly is simply the enthusiastic chemistry between Seth Rogen and Rose Byrne, and the movie's overall sweet nature that ultimately balances out its baser conduct. For all of the feuding and low blows, Stoller avoids going too dark, creating an all-in-good-fun tone that spreads to the viewer. In the midst of dildos galore, a seemingly used condom that Stella finds, and some nefariously placed airbags, Mac and Kelly—and, for that matter, Teddy—stand at a turning point, the next phases of their lives fast approaching, as they do for all of us. "Neighbors" isn't a great movie, but there is a universality to its themes that rings true.