Multiplex summers have long been the province of lewd comedies, stretching back to the glory days of the ’80s.

The past few summers, however, have brought ostensibly funny movies forsaking the fundamentals — interesting characters, compelling stories, relatively fresh takes on genre tropes — and instead intent on going for broke.

There are exceptions — "Bridesmaids" memorably broke the mold in 2011, and Seth MacFarlane’s "Ted" was rejuvenating last year — but the recent majority of studios’ summertime sillies have been trying way too hard.

‘WE’RE THE MILLERS’ Rated: R Opens Today

Thankfully, "We’re the Millers" falls into the exception category. Anchored by breakout performances from Jason Sudeikis and Will Poulter, "Millers" is a raunchy, hilarious and ultimately sweet-natured riff on the tried-and-true road trip comedy.

Directed by Rawson Marshall Thurber from a screenplay stitched together by four credited authors (Bob Fisher, Steve Faber, Sean Anders and John Morris), the film wastes little time establishing its straightforward premise.

Low-level pot dealer David (Sudeikis) is robbed, and forced by his friend and boss, Brad (Ed Helms), to head south of the border and return an RV full of weed over the Fourth of July weekend.

In order to blend in and avoid the suspicion of authorities, David hits upon the idea of recruiting a fake family: stripper neighbor Rose (Jennifer Aniston), troubled runaway Casey (Emma Roberts) and awkward teen Kenny (Poulter). The foursome sets off to retrieve the marijuana, and all manner of off-color hijinks occur — including a horrifyingly memorable (and incredibly uncomfortable) spider bite.

As with "The Heat" earlier this summer, "Millers" walks a tricky tightrope between violent action and gasp-inducing comedy, albeit more successfully.

"We’re the Millers" is far more concerned with its off-kilter nuclear family than the stakes of completing a drug deal, allowing the story to unfold at a more leisurely pace. The film sags in places — at nearly two hours, "Millers" could benefit from a few trims here and there — but shines when the cast, fueled by tremendous chemistry, is allowed to cut loose and tear into a series of juicy comic set pieces.

Sudeikis, in his first film since confirming his exit from "Saturday Night Live," manages to make his selfish, glib drug dealer sympathetic, as well as humorous, and suggests he could have a future with more dramatic parts. Aniston, continuing her foray into racy comedic roles (after 2011’s "Horrible Bosses" and last year’s "Wanderlust"), finds nuance in what could have been a thankless part. Roberts and co-stars Helms, Nick Offerman and Kathryn Hahn also turn in strong work.

But no one else on screen comes close to the performance delivered by the British Poulter, who is all but unknown to American audiences (he was the lead in the little-seen 2007 gem "Son of Rambow").

His Kenny is a figurative and literal punching bag for almost every other character, but Poulter conveys dignity and childlike wonder at every turn, even during some of the most outrageous sequences.

It’s a terrific piece of acting — even his spot-on rendition of TLC’s "Waterfalls" — and like Zach Galifianakis’ turn in the original "Hangover," one that will mark his arrival in Hollywood.

"We’re the Millers" arrives at a familiar destination, but as summer comedies go, the scenery along the way is riotously, refreshingly funny.

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Review by Preston Jones, Fort Worth Star-Telegram