In the opening moments of the Marvel comics-inspired “Ghost Rider,” the camera pans across a nighttime desert landscape while Sam Elliott’s parched baritone narrates a predictably cartoonish-sounding premise. In every generation, legend has it, the Devil has enlisted the services of some menacing mortal to be his personal bounty hunter — his Ghost Rider.

“The thing about legends is,” that familiar cowboy drawl continues, “sometimes they’re true.”

But mostly, they’re not true. In the case of “Ghost Rider,” they’re not even remotely plausible, although not because of the fantastical plot devices. Phantom motorcycles, contracts with the Devil and skulls catching on fire are all relatively easy to believe when placed alongside the movie’s much more bewildering enigma: why, in blessed creation, would the Prince of Darkness decide to outsource one of his vital administrative positions to a protagonist played by, of all people, Nicolas Cage?

Protagonist is probably too strong a word for someone like Johnny Blaze, Cage’s cheap fiberglass mess of a character, because it suggests the possibility that an audience somewhere might mistake him for a real human being and might therefore assign their sympathy to him. True, motorcycle stuntmen like Johnny aren’t the most universal characters in all of literature, but the real shame is that, as comic-book movies go, “Ghost Rider” tosses up a plotline with the potential for some fairly serious character development: Johnny sold his soul to the Devil (Peter Fonda) as a teenager in order to save his ailing father, and now he must use his demonic powers to serve his master at night even while striving to do good during the light of day.

Those demonic powers, by the way, involve transforming into a flaming CGI skeleton with a high-powered bike, a steel chain for a whip and an apparently-unchecked license to violate every conceivable law of science. The Ghost Rider can also kill somebody simply by making eye contact, notwithstanding the fact that skeletons generally don’t have eyes.

If Johnny’s situation provokes any sort of inner conflict, it barely manifests as such. Instead, Johnny is merely a neurotic parody of Evel Knievel who listens to The Carpenters, eats jelly beans out of martini glasses and stares at himself in the mirror while muttering, “You can’t live in fear.”

Worse still, he’s accompanied by his chubby handler, Mack (Donal Logue), who does little except discharge one after another of those concerned-sounding lines that characters named Mack usually say. When Johnny starts reading all sorts of “religious stuff,” (which, in this movie, means that he hurriedly rips a few pages out of a very old volume of “Faust”), Mack implores: “Johnny, where’s your head at?” as if the ’70s easy listening weren’t weird enough already.

At another point, Mack redirects a would-be interviewer away from Johnny by telling her, “Look, lady, I don’t know how many years you’ve been doing your job, but Johnny Blaze don’t do interviews.” Well, nobody knows how many years Mack’s been doing his job, but it’s fairly obvious that Johnny Blaze is out of his gourd. Jelly Bellies and occult reading material aside, it must take a pretty whacked-out biker to spurn the jaw-dropping love interest Roxanne (Eva Mendes, looking better than ever) in order to retain the ability to light on fire.

One wishes that such an obvious lack of internal logic were the result of some deliberate decision by the production team, but that’s highly unlikely. At one point, when Sam Elliott enters the film as a character — a wizened old coot of a gravedigger who’s little different from any of Elliott’s previous roles — he motions to the cemetery behind him. “Ironic,” he says. “Got a lot of irony around here.”

If only. Like the movie’s opening frames, which seem to be an overt reference to “The Big Lebowski,” most of what passes for style in “Ghost Rider” is really just an empty glibness, a tactless grab for something — anything — to keep the dismal project afloat. It’s no coincidence that in the movie’s long parade of special-effects conflagrations, irony makes nary a single appearance.

And so, when Johnny and Roxanne kiss by the side of the highway, a cow inexplicably moos. When Ghost Rider gets slammed by a tractor-trailer, the camera cuts to a sign on the back of the vehicle that reads, “How’s My Driving?” And when the movie’s hell-spawned villain Blackheart (Wes Bentley) is confronted by a Catholic priest, he grins and says, “Forgive me, Father, for I have sinned. I’ve sinned a lot.”

Bringing up the topic of sin should imply some possibility of redemption, but in “Ghost Rider,” it seems as if there’s no such thing as God; there are only bad guys (like the Devil) and really bad buys (like Blackheart, who’s played with the same creepy calm exhibited by Bentley’s character from “American Beauty.”) One is tempted to say that “Ghost Rider” is only redeemed from its sins by the fact that it’s not completely boring. But even that might hold true only for the first viewing.