“Novocaine” is an action comedy about a white-collar nebbish whose congenital inability to feel pain becomes an advantage once armed thugs kidnap his girlfriend and he becomes hell-bent on rescuing her by himself. Hearing this description, it’s easy to imagine some kind of hybrid of twee workplace comedy and eye-gouging violence, the kind of movie where a guy can slaughter roomfuls of people and still hold his drinks down at trivia night.

What a surprise to find a film that’s actually thoughtful about the consequences of violence, that doesn’t see people as disposable targets but treats death with the finality it deserves. It’s actually about this man and his condition rather than just using the circumstances of his life as an origin story.

Jack Quaid plays Nathan “Nate” Caine a few clicks south of Bill Nye the Science Guy. He’s a nice, quiet fellow who’s thankful for his job as an assistant bank manager, mostly because it allows him the opportunity to hide in an office and not talk much about his life. That life, we gather, consists mostly of playing RPGs in a starkly furnished apartment and not keeping in contact with anyone. When he runs into two of his middle school bullies at a bar, we learn that “Novocaine” is not a name he gave himself — and realize in a flash not only how sad this man’s life must have been, but that the movie is actually taking that fact seriously.

As he enters his 30th year of being sheltered, thoughts of mortality and missed opportunities swirl in his craw, especially when he starts seeing Sherry (Amber Midthunder, from “Prey”) around the office. Sherry sizes him up and wonders how such a decent, handsome and well-paid man could spend his life as a celibate recluse. This leads to a variation of one of the best scenes in “Some Like It Hot” — not the one you’re thinking of — and the scratchy beginnings of a relationship, complicated by Nate’s instinct for self-sabotage.

Goons in Santa suits stick up the bank and take Sherry hostage. This unleashes the lion in Nate, who we sense has spent his whole life passively letting people whale on him. He’s as scrappy a fighter as his condition allows him to be, surprising bigger and badder enemies who never expected to be bested by a 120-pound guy in a suit, but he never becomes a cold-blooded killer. He’s almost Charlie Brown-like in his decency; when he wins his first fight, he asks his opponent if he’s OK (he’s not).

Though the Christmas setting suggests “Die Hard,” the film frankly feels like a response to the tendency in action comedies like the “Kingsman” and “Kick-Ass” franchises to treat flesh-and-blood bad guys like targets in a video game while defusing the carnage with pop needle drops and snarky jokes.

Nobody dies in this movie before we get to know them. There are only three people in the gang Nate goes after, and when one of them gets shot, the film gives us not one but two scenes of his brother worriedly wondering where he is. Later, we glimpse a framed photograph in the dead man’s home, showing a woman that must be his mother.

There’s witty repartee, but the movie doesn’t feel like it has to be funny all the time. Some of the earlier scenes are very serious indeed, showing two smart and sensitive people growing closer to each other and sharing their scars. Even the score by Lorne Balfe and Andrew Kawczynski seems to wish them well, underscoring the precarity of their situation with yearning string swells.

Of course, you’re not buying a ticket to “Novocaine” to see two hearts beat as one. You’re buying a ticket to see Jack Quaid get the crap beaten out of him, get back up and dish some serious damage out in turn. What makes it more than a novelty is how much feeling there is in all of it, how all the ridiculous things he does are charged by his love for Sherry and his determination not to let the best thing in his life pass him by.