Imagine the craziest thing you’ve ever done, and it will still pale in comparison to what Chicky Donohue did back in the late 60s. When his best friends went to fight the war in Vietnam, Chicky later made the ballsy decision to deliver beer to them inside the line of fire. Some would call it very stupid, while others would label it the most heartfelt gesture a friend could do.

It’s that earnest juice that fuels Peter Farrelly’s likable true story-based film about one man’s wild idea of purpose at a time when the nation was fracturing with a war that few could explain. Played with aloof exuberance by Zac Efron, Chicky is a former marine drinking away the rest of his youth as a part-time merchant seaman still living at home. When one of his closest friends goes missing overseas in battle, Chicky’s wild idea of finding him includes bringing cold ones to the rest of his buddies. Through this struggle, he gets to see how different this war is from previous ones.

A balance in tone isn’t always Farrelly’s best friend here, as the movie struggles to decide on being a full-blown drama or a comedy with some serious bones attached. Overwrought acting from a portion of the cast and a TV movie of the week vibe set off warning signs early on, but that’s swept to the side as soon as Chicky’s adventure escalates from one troublesome situation to the next, one that includes a run-in with a war photographer (Russell Crowe, putting in decent work.)

The movie doesn’t overstay its welcome either, choosing understated power in its dedication to the Americans lost in that awful war. While the aloofness of its protagonist extends to the screenplay and aesthetic of the movie, “The Greatest Beer Run Ever” knows how to mortgage its power, especially in a late scene with Chicky riding in a plane alongside fallen soldiers. Those moments interchanged with the lighter, more humorous aspects of the story mix well, giving the viewer new knowledge and an underdog story that moves.

Efron makes it work througout, combining the movie star looks with a compelling character. He doesn’t overdo the accent or the person, sliding easily into the body and mind of a guy who was constantly underestimated and carried a heart big enough for two people. After serving his country and finding a half life in the sea, Chicky was compelled to do something extraordinary, and he pulled it off.

Efron convincingly plays a role that is tailored to his strengths yet presents a few new challenges. We instantly like and believe in Chicky, something that extends to its star doing the right things in the role. Crowe doesn’t do any extra heavy lifting in his role, and Bill Murray has a small role with an overworked accent as a retired Colonel. Jake Picking, a lesser known young actor, puts in fine work as a friend from home whom Chicky runs into during his beer run.

“The Greatest Beer Run Ever” informed me about an improbable story that I and several others had no idea existed, which is always a fun way to get into a movie. It’ll get you acquainted with a guy who didn’t think impossible was a thing. It’s a detached joy to watch a movie where a character does something you would never dare do, and later find out that it really happened.

When asked late in the film what he plans to do with the rest of his life, Chicky’s reply is succinct: “Less drinking and more thinking.” Words of wisdom from a movie that isn’t going to win any awards, but should deliver a good time. If you like an earnest film with an aloof mind, and some Zac Efron action, then give “The Greatest Beer Run Ever” a shot. It’s streaming on Apple TV Plus.