The unwieldy action rom-com “Novocaine” makes a convincing argument that its lead, Jack Quaid, can do it all: woo the girl, shoot the goon and tickle the audience. The movie itself has a harder time, screwing its three genres together so awkwardly that it tends to limp. Directed by Dan Berk and Robert Olsen from a script by Lars Jacobson, it’s about a San Diego assistant bank manager named Nathan Cane (Quaid) with congenital insensitivity to pain — a rare and real condition in which a person can’t feel cuts, burns, bruises and broken bones. All of the above injuries (and more) happen to Nathan after his workplace crush Sherry (Amber Midthunder) gets kidnapped by bandits. He’s no ass-kicking gym rat; he’s simply willing to take any punishment to get her back.

How seriously should we take this premise? Very, according to the grisly blood splatters, the ham-fisted dramatic score and the panic in Midthunder’s eyes. Also, not seriously at all, gauging from the comic relief that’s haphazardly bolted onto the plot, such as a cop played by Matt Walsh who gripes that San Diego’s gone to seed ever since “the Chargers and the Clippers betrayed us.”

Of the torment Quaid endures, his hardest challenge is straddling the tone. He’s charmingly chipper while being shredded to machaca. “It’s fine!” he insists, as a knife plunges through his hand. “Good to go!” he says, carving a bullet out of his arm with a box cutter. Our vicarious shudders come only from the sound design, which gives a horrific squelch to the shock of a medieval mace slamming into Nathan’s back. (“Why?” Nathan sighs with exasperation, as though he’s merely gotten stuck at a red light.)

The slapstick works, particularly when Quaid does a Chaplin-esque shuffle with an arrow sticking out of his thigh. But what works better is the opening act, a kooky but sincere indie romance that only has a few scenes to convince us that Nathan’s chemistry with Sherry is worth putting himself through a meat grinder. Nathan looks like a typical sad sack — drab apartment, droopy corporate wear, anxious forehead crinkle — with the twist that he’s been raised to be terrified of everything, from scalding himself in the shower to accidentally chewing off his own tongue. (Production designer Kara Lindstrom establishes a life story of injuries by sticking tennis balls onto every sharp corner of his furniture.) At work, this isolated oddball shows empathy to a cash-strapped widower (Lou Beatty Jr.), proof that he at least feels emotional pain. Still, he’s caught completely off-guard when the office cutie scalds him with coffee (no biggie) and then apologetically asks him to lunch (yikes).

Sherry comes on so strong, we want her checked for Hollywood’s chronic disease: manic pixie dreamgirl syndrome. To the script’s credit and Midthunder’s convincing zeal, Sherry has her own motives for making it work, including a need to stick up for the weak. And we have a question we’re hoping she can answer: If Nathan can’t feel pain, how can he feel pleasure? When Sherry prods him to take his first bite of solid food, Quaid does for the cherry pie what his real-life mother Meg Ryan once did for the pastrami sandwich. His eyes flutter in ecstasy. He’s in love.

Even knowing that this ridiculously charming setup will take a sharp veer into blood and guts, the dramatic tonal change still hits us like a kick to the head. Once a trio of robbers (Ray Nicholson, Conrad Kemp and Evan Hengst) barges into Nathan and Sherry’s bank and quickly and coldly murders four people, the movie doesn’t have any more swoon-worthy moments in it other than Nathan defibrillating himself so that he can keep on going. Midthunder’s character gets especially robbed. She may as well be John Wick’s puppy.

Co-directors Berk and Olsen spend the rest of the film trying to make a spiritual sequel to Jason Statham’s “Crank,” the ultimate whackadoo action flick about an assassin who pumps himself up to stay alive (bested only by its sequel, “Crank 2: High Voltage”).
Quaid doesn’t have Statham’s biceps, but for my money, he doesn’t need them. He has the perfect look for this movie. Lean and rumpled in unusual places, he’s half-twerp, half-man. Smartly, the stunt choreography doesn’t position its protagonist as a super fighter. The gasps come not from his skills, but from what he’s willing to do to win: grind glass into his fists, grab a scorching cast-iron skillet without mitts, plunge his right hand into a deep fryer until it blisters like a samosa. There’s an extended squeamish groan when, having seized and fired a boiling gun, it doesn’t occur to him to drop it. Visually, the violence is shot in sickening close-ups. Cartoonish horseplay would have gotten a hardier laugh.

The camera hurls itself into the high jinks, slamming itself back and forth at the same cadence as Nathan’s concussions. But it’s more fun watching him take abuse than dole it out. When this sweetheart goes on the attack, the effect is like watching a bunny with rabies. You’re just thinking someone should take the poor dear to the doctor. (Meanwhile, the directors mistakenly think we’ll enjoy it more in slow-motion.) Even in the moments designed for cheers, like when Nathan destroys a bad guy’s swastika tattoo, you don’t really want that agony on his conscience.

Which is why the best fight scene involves psychological combat. A tied-up Nathan tricks his executioner into giving him extra time to figure out an escape by going full Br’er Rabbit, pretend-begging the killer to get his torture over with fast. “Not the pliers — please, not the pliers,” he pleads. Let me try that myself. Don’t put Quaid in a romantic comedy — please, not a proper romantic comedy.