“Full Metal Jacket,” “Saving Private Ryan” and “Apocalypse Now” are a handful of titles that surface during discussions about movies that capture the genuine gravity of war.

But when audiences think of a film about a layabout merchant mariner from New York bringing his friends canned beer in 1967 Vietnam, comedic anticipation is bound to follow — and they’d be right, sort of.

Directed by Peter Farrelly (”Green Book,” “Dumb and Dumber”), “The Greatest Beer Run Ever” is both a comedy and drama that captures the ironic and inherent humor that so often accompanies war.

Though it’s not seamless, the movie, based on the true story of John “Chickie” Donahue, has good fun with the absurdities of the Vietnam War while offering poignant reflection of the conflict’s traumas.

The film begins with Chickie, played by Zac Efron (and his new chin), drunkenly proclaiming he’s going to Vietnam to bring beer to the boys from his Inwood, New York, neighborhood. Chickie’s quest is viewed through the lens of a blissfully naive patriot, one who believes, like many at the time, that the U.S. was fighting and winning in Vietnam. And even though protesters may not support the war, others like Chickie still consider the troops heroes.

After boarding a merchant ship and arriving in Saigon, an unaware Chickie sets out with the belief that his mission is really no different than that of a simple Pabst delivery man. And he somehow retains that sort of incredulity for much of his story, even as he dodges bullets between trenches in LZ Jane.

It isn’t until about halfway through the film, when Chickie witnesses a CIA operative throw a hostage from a helicopter, that he begins to see things as they really are. This, and his evasion of friendlies while pretending to be a CIA member, is when the film really turns a corner.

In one scene, Chickie encounters a young Vietnamese girl playing on a dirt road. Rather than engage, the girl slowly retreats and begins to cry, prompting the arrival of her mother, who quickly sweeps her daughter back into the fields and away from the perceived threat.

There, it dawns on Chickie that the Vietnam War is perhaps not all that it seemed to be on televisions back home. At the advice of his friends, to whom he did manage to deliver a couple warm beers, Chickie opts to return home, lessons half-learned.

Still, it’s when Chickie finally makes it back to Saigon that “The Greatest Beer Run Ever” takes a turn as a serious war film. His arrival happens to fall on the date that North Vietnamese and Viet Cong forces launched a surprise attack on the south, the first day of the Tet Offensive.

Dramatic scenes of city-wide guerrilla warfare starkly contrast those at the film’s beginning, but this is where it truly shines as a genuine portrayal of war, juxtaposing scenes of humorous chaos and unwitting troops with a brand of unpredictable hostility unique to combat. And while the film takes a while to get there, it does so with aplomb.

“The Greatest Beer Run Ever” isn’t exactly a new story, nor is its message about blind patriotism, which feels especially pointed today, but it is a good, hard look at war as an experience through nascent eyes.

It may be a movie about beer, but it is, in fact, quite sobering.

“The Greatest Beer Run Ever” is in theaters and available to stream on Apple+.

Originally published by Military Times, our sister publication.