The moronic Fred Simmons (Danny McBride) would be just another tired spin-off of Napoleon Dynamite were it not for his profession. Fred, the martial arts instructor at the center of Jody Hill’s “The Foot Fist Way,” isn’t just oblivious to his many flaws — to the contrary, he makes a living from the belief that he’s superior to those around him.

It is a small but important distinction, and one that raises the movie above such lovable-outsider fare as “Nacho Libre,” “Hot Rod,” and “Charlie Bartlett.” In this era of ugly comedies that ask us to mock someone’s shortcomings, “The Foot Fist Way” — the literal translation of “Tae Kwon Do” — is about one loser’s misplaced and severely bloated confidence. What’s funniest about Fred’s universe is not that he gets mocked by his peers, but that he seems to have convinced others to drink his peculiar brand of Kool-Aid.

Owner of his own small-town tae kwon do school, and teacher to students ranging in age from 5 to 65, Fred is a fiery, arrogant prima donna. But before we see him swagger, Mr. Hill ensures that we see him stumble. As he sets up a tent in a parking lot, determined to wow parents into trusting him to teach their children, something is gleefully askew in his demonstration. Fred stands next to two students who look less than eager to be there, and he’s performing for about a dozen spectators who seem to share that sense of indifference. Fred awkwardly kicks and karate chops his way through a series of wooden boards held aloft by his assistants. But when one of the demonstrations goes bad, Fred throws a fit and blames his student helpers.

In a rush, we learn nearly everything we need to know about Fred, an unlikely sensei who has managed to stay afloat by operating a dojo out of a strip mall. He aims to be a good teacher, but his insecurities and immaturities won’t let it happen. As Mr. Hill cuts from one class session to the next, adopting a handheld aesthetic that leaves the film looking like a documentary made on the cheap, we realize that the pupils are actually much more involved than the teacher. Fred is oblivious to the toddlers throwing punches like maniacs, just as he is clueless about his inappropriate behavior toward female students. When his adulterous wife challenges his masculinity, Fred takes out his rage on unsuspecting 8-year-olds.

Mr. McBride so completely sells us on the fact that someone like this actually exists that we can’t help but get caught up in the train wreck. Once it has been established that Fred has no business interacting with children, the second half of the film turns the protagonist into a child by sending him in search of his hero, Chuck “The Truck” Wallace (Ben Best, one of the film’s co-writers), the eight-time undefeated champion and star of the “Seven Rings of Pain” trilogy.

After Fred hops in the car to attend a fighting convention where Chuck is appearing, he suddenly becomes the one who looks up to a mentor who couldn’t care less about him. Learning to hate the man he once admired, and forced to question his own skills, Fred finds his world turned upside down, his rage replaced by a permanent state of depression.

It’s been more than two years since “The Foot Fist Way” made its premiere at the Sundance Film Festival. Ironically, though, the movie may benefit from the lengthy delay. In recent years, we’ve grown accustomed to this faux documentary approach. On television, in particular, “The Office” — a similar product about a profoundly flawed boss — has become a huge hit. And as with the laughs generated in that series, we chuckle not only at Fred’s delusions of grandeur but at the wide-eyed, astonished reactions from his students.

Mr. Hill’s best decision may have been casting amateur extras in the film, because it appears, at least, as though they really can’t contain their bewilderment. Some of Mr. McBride’s shtick grows stale, trapped within a narrow range of emotion, but what keeps things churning is this believable tension between an actor going for broke and the hyper-realistic world that surrounds him. There are times when Fred’s students appear genuinely shocked by what’s coming out of his mouth. It feels like we are watching a series of outtakes rather than a scripted interaction. In the movie’s most inspired moments, the train wreck doesn’t seem staged.

ssnyder@nysun.com