I’m going to explain what “Faster” is about, so pay attention and try to keep up. It’s about a man who gets out of prison and goes around killing the people responsible for putting him there. The end.

If it seems like I have glossed over some of the nuance, believe me, I have not. If anything, it’s less complex than I’m making it sound. And there’s nothing wrong with a movie being simple and to-the-point, even ludicrous — but shouldn’t a ludicrous movie about revenge and bloodlust be more fun than this?

The ex-con with the murderous agenda is identified only as Driver. He is played by Dwayne Johnson, who does not seem as excited to have escaped Disney’s family-friendly clutches as he ought to be. Driver helped a group of criminals, including his half-brother, pull off a Bakersfield bank heist a decade ago. (Driver drove the getaway car, duh.) Someone ratted them out, though, leading to Driver’s incarceration and everyone else’s death. The minute Driver gets out of prison — I mean the very minute — he heads to a wrecking yard, where a classic car, a gun, and a print-out of Google Map directions are waiting for him. He’s got killin’ to do!

Driver is brazen about his work. He does not seem to fear being caught. He’ll walk into an office and shoot a guy in broad daylight. He’s hardcore like that. (The prison warden, played by Tom Berenger, identified this trait in Driver: “It’s as if you were born to the darkness in this place.”) Driver’s activity draws the attention of the police, including a clean-cut homicide detective named Cicero (Carla Gugino) and a washed-up junkie detective only identified as Cop (the always-lively Billy Bob Thornton). In case you were wondering, Cop is a couple weeks away from retirement.

We are also introduced to Killer (Oliver Jackson-Cohen), an assassin hired by one of Driver’s targets to prevent Driver from finishing his to-do list. Killer is a millionaire, a software developer, a yoga enthusiast, and a thrill-seeker. Referring to the yoga position, Killer’s girlfriend (Maggie Grace) says, “Sometimes I’m afraid a real ‘corpse pose’ is the only thing that’s going to satisfy you.” Photos show that Killer couldn’t walk when he was a child, and scars on his legs indicate major surgery. Does any of this matter? Not a bit. But the movie seems intent on making sure we know it anyway. I wonder if there’s a half-hour of deleted scenes that flesh out all these backstories.

I have made allusions to the goofy dialogue, courtesy of screenwriters Tony Gayton (“The Salton Sea,” “Murder by Numbers”) and Joe Gayton (“Uncommon Valor”). Would that the film were aware of its goofiness, even a little! What should be a brainless but entertaining shoot-em-up flick is, in the hands of director George Tillman Jr. (“Men of Honor”), just moody and bleak. Dwayne Johnson tamps down his considerable charisma and makes Driver a blank slate. This character is supposed to be calculating and cool, but he isn’t. He’s boring. It’s great to have The Rock doing action movies again, but not if they’re going to be forgettable misfires like this.

C- (1 hr., 35 min.; R, some very strong violence, moderate profanity.)