Proximity to Canada is probably the single greatest predictor of who will walk away from “The Promotion” satisfied. A feature-length exercise in passive aggression and antagonism that doesn’t so much boil over as occasionally bubble to the surface, Steve Conrad’s film, opening Friday, is a comedy of restraint that almost seems out of place in an era when “You Don’t Mess With the Zohan” is considered standard operating procedure.

As “The Promotion” toured the festival circuit earlier this year, it earned the ire of critics who seemed stunned that a comedy starring John C. Reilly and Seann William Scott would unfold with such little zaniness, and at such a low volume.

But one wonders if the same scorn would have been heaped upon it had the film arrived in theaters with another of its rumored early titles: “Quebec.” Is it possible that early audiences would have responded differently, recognizing the story not just as being about two guys and a grocery store, but about the wider quirks of a culture?

Anyone who has lived in Canada, or in a Midwestern city with a Scandinavian heritage such as Chicago, where “The Promotion” takes place, should respond warmly to Mr. Conrad’s approach to this story of quiet, deceptive blue-collar office warfare. If NBC’s “The Office” has a meaner streak to its rendition of office culture, then “The Promotion” is the more pitiable and introverted side of the familiar coin.

The two go-nowhere central characters are Doug (Mr. Scott) and Richard (Mr. Reilly), and the promotion in question involves the building of a sparkling new Chicago supermarket. Both are employees of the supermarket chain, both are frustrated by their emasculating lots in life, and both realize that the creation of a new managerial position could be a ticket to the middle time.

Mr. Conrad’s script adroitly presents the ensuing war as one waged with hollow smiles and pleasantries, but what’s more intriguing here is its pitting of conflicting cultural mind-sets, namely the Midwesterner’s reputation for being the good guy and the American drive to stomp one’s competitor into the ground. Doug is the eager beaver who wants to be the boss of everyone with whom he can’t be friends. He hides negative customer comment cards from his superiors. When he sees that Richard has befriended the store’s regular soda vendor, he must find his own vendor to bond with. And when news of the big promotion springs up, he essentially promises his wife (Jenna Fischer) that better days are on the horizon.

Richard is the new guy from Canada, pleasant to a fault, who has relocated to America for work. It isn’t until later that we begin to gain insight into his dark backstory. The bigger he smiles, the more unnerving his good-guy act becomes, and the more Doug starts to wonder: Is Richard genuinely affable, or is he erecting the same false façade?

Mr. Conrad tosses us into the monotony of the grocery store, poking fun at the minutiae that dictate Doug’s and Richard’s job responsibilities.

With each passing week, however, the tension between the two escalates, and as the interviews for the big promotion draw near, what was ho-hum becomes cutthroat.

There’s a sad but believable cynicism to “The Promotion.” Doug and Richard couldn’t care less about this boring day job, despite the lengths to which they will go to protect it, and both should be trying to find employment in a field that actually excites them. But they are scared of abandoning the familiar, and their inner conflicts morph into outer conflicts, where proving that they are customer-service champions clashes with dreaming of the day when they won’t need to mop up spills and retrieve carts from the parking lot.

It’s true: The film’s darker underside does not make for a laugh riot. Ultimately, “The Promotion” is about people trying to bury their natural instincts, and to substitute being a perfect employee for being a fallible human. As Mr. Scott tries to suppress his inner Stifler, and as Mr. Reilly fights mightily to keep his grin big and bright, “The Promotion” becomes an entertaining waiting game. Buried beneath all these Midwestern niceties, we know there’s a raging New Yorker waiting for the opportunity to scream back at a customer.

ssnyder@nysun.com