BULLET TO THE HEAD is a stiff movie. But it's not just stiff in one way; it represents a rainbow of stiffnesses. It is arthritic. It limps. It's inflexible. It's starchy. It's like an army of men in Arthurian suits of armor doing a triathlon: kind of funny, mostly plodding, and then tragic when it comes time for the swimming competition.

The script is stiff-backed, making awkward gestures toward the basic plot elements: A hired killer with the unfortunate nickname of Jimmy Bobo (Sylvester Stallone) gets sucked into some sort of shady real-estate deal that requires him to partner with a cop (Sung Kang) and bump heads with an evil condo aficionado (Adewale Akinnuoye-Agbaje) and his crew of weasels (Christian Slater) and cutthroats (Jason Momoa). But the dialogue is packed with dull exposition and dumb repetition. At the scene of the hit that opens the movie, Jimmy Bobo admonishes his doomed partner: "Don't forget to get his watch and wallet." "Right," his partner over-explains to nobody. "It needs to look like a break-in."

Stallone is stiff like an infected toe, swollen and painful to look at. He doesn't talk so much as moan, and the audience at the review screening I attended laughed at his one-liners not because he possessed a charming self-awareness, but instead because he sounded almost human. (Even more painful: Most of his "jokes" consist of racist nicknames for his Korean partner, like "Oddjob" and "Confucius.") The only exception to the parade of awkward pauses that is Bullet to the Head: The eminently watchable Jason Momoa (Khal Drogo from Game of Thrones, Conan from that already-forgotten Conan reboot), who, with his natural charisma, resembles nothing so much as an evil Chris Hemsworth. It can't be a mistake that most of the handful of nasty, entertaining scenes that somehow managed to survive the making of Bullet to the Head belong to him.