If filmmaker Kevin Smith lived in olden times, and had a family coat of
arms, it would probably have a phallus and giant lit doobie on it, and
maybe some sort of animalistic violation. Smith, of course, burst onto
the scene in 1994 with the ultra-low-budget, delightfully lewd Clerks,
and has since then, while various indie film trends have waxed and
waned, by and large hewed to the same sort of hyper-literate puerile
humor that defined his debut. Injections of more overt sentimentality
(as in Jersey Girl, for instance) have proved Smith a sometimes ham-fisted peddler of sincerity, so it’s a good thing that his new film, Zack and Miri Make a Porno, counterbalances a third-act romantic awakening with such a heaping helping of filthy fun.

Things look grim for lifelong friends and roommates Zack (Seth Rogen) and Miri (Elizabeth Banks) when an escalating mountain of debt results in their electricity and water being cut off, just in time for winter. A chance encounter at their high school reunion with the gay porn star boyfriend of a former classmate, though, sparks an idea in Zack: they can get out of debt by making their own homemade skin flick.

Recruiting a motley crew of off-screen assistance (Craig Robinson, Jeff Anderson) and on-screen “talent” (Jason Mewes, Ricky Mabe and adult film stars Traci Lords and Katie Morgan), Zack and Miri set out to shoot an adult Star Wars spoof, only to find their budgeted plans ruined at the last moment. Re-jiggering ideas on the fly, they end up shooting after-hours at the coffee shop where Zack works. The two vow that having sex won’t ruin their friendship, but when filming begins what started out as a business proposition turns into something much more.

Rogen might be somewhat overexposed, it’s true, but he’s a natural fit for schlubby misfits like this, and he and the superlative Banks — who can do both sunny and salty, with equal skill — have a nice chemistry together. Smith’s touch with hilariously raunchy dialogue, meanwhile, is still virtually unparalleled. (“Gimme two popsicle sticks and a rubberband and I’ll find a way to fuck it, like a filthy MacGyver,” rants Zack at one point, illuminating the differences between men and women’s masturbatory aides.) That’s certainly what powers the movie, and gives it its kick. In terms of structure, though, Smith also smartly dispenses with any potentially distracting sideplots by having Zack and Miri’s families already out of the picture.

At its core, Zack and Miri is about the transformative power of sex, and how special that bond can be. If Smith hasn’t quite found a way to convincingly seal the deal, narratively speaking (the jump forward in time that precedes the closing 20 minutes comes off somewhat contrived), the candor and bluntness with which Zack and Miri deal with one another — devoid of any of the typical polite gender-identified boundaries — at least mark it as a realistically blue 21st century love story. (The Weinstein Company, R, 101 minutes)