As if it weren’t bad enough that we’ve had to put up with all of Charlie Kaufman’s self-consciously clever yarns, we’re now beginning to get mediocre imitations of them like Michel Gondry’s “The Science of Sleep” and this effort from first-time scriptwriter Zach Helm, directed by the extremely variable Marc Forster (“Monster Ball” and “Neverland,” but also the misguided “Stay”). It might be more accurate to say that “Stranger Than Fiction,” about a fellow who begins hearing a voice in his head that persuades him he’s not only a character in a novel but one who’s about to be killed off by its author, actually owes a great deal both to Kaufman’s existential puzzlers (“Adaptation” in particular) and to Peter Weir’s “The Truman Show” (1998), with which it shares the notion of a man trapped in a fictionalized life as well as the device of placing a wild-eyed comedian (there Jim Carrey, here Will Ferrell) in a role that calls for restraint. (Not to mention Pirandello and even Rod Serling–check out the Twilight Zone episode titled “Five Characters in Search of an Exit.”) But it’s Kaufmania that’s really prepared the ground for films of this ilk.

The complicated lineage demonstrates, though, that despite its pretensions to be unusual, “Stranger than Fiction” actually seems oddly imitative and ordinary. Ferrell plays Harold Crick, a Chicago IRS man who leads a thoroughly repetitive, precise life, one of obsessive order, down to counting the number of tooth-brush strokes he employs each morning. One day he begins hearing a woman’s voice narrating his actions as he performs them, as though she were the “author” of his life. He consults a psychiatrist (Linda Hunt), when it appears the narrator might have a demise in store for him, who in turn suggests that he go see a professor of literature, Julius Hilbert (Dustin Hoffman). Before long Crick accidentally stumbles onto the identity of his “creator”– tense, reclusive Kay Eiffel (Emma Thompson), a distinguished novelist who hasn’t produced a book in years and is blocked about how to end the one in which Harold stars, a situation that’s prompted her publisher to assign her a disciplined assistant (Queen Latifah) who might help her over the hurdle. But simultaneously Crick has taken Hilbert’s advice to live his life less rigidly, and has fallen for Ana Pascal (Maggie Gyllenhaal), a free-spirited baker who–following the convention obligatory to the genre–initially brushes him off but gradually warms to him. The emotional attachment makes it all the more imperative that he locate Eiffel and convince her to keep him alive.

When you take the trouble to parse “Stranger Than Fiction”–which may take more effort than it’s worth–the plot doesn’t make much sense. (Is he a fictional figure plopped abruptly into a real world, or wouldn’t all the other characters be as fictional as he is? And mustn’t his self-realization be part of Eiffel’s plot?) And even if you’re willing to set that aside, the way in which Helm chooses to end the tale owes more to the contemporary demand for happy endings than to even the most rudimentary logic. It could also be argued that the bits and pieces we see (and hear) of Eiffel’s novel make it sound like a pretty mediocre piece, rather than the literary masterpiece Hilbert proclaims it to be at first reading. But apart from the sophomoric nature of the premise, the execution of it isn’t strong enough to save the enterprise. Though the production is mostly good from a technical perspective, Roberto Schaefer’s lensing doesn’t give the Chicago locations any particular distinction, and Kevin Thompson’s overall visual design isn’t as imaginative as one might hope.

But ultimately it’s the cast that fails to keep things afloat. The best contributions are from Thompson and Hoffman. Her turn as the uptight, chain-smoking writer is more caricature than performance, but she’s fun to watch nonetheless. And Hoffman, going for broke as is his wont nowadays, is thoroughly engaging as a single-minded (though overworked) academic. Unfortunately, these two are on the periphery of the action, and at center stage Ferrell comes across as merely adequate–more restrained than usual, of course (one great consolation is that at least he doesn’t strip down to his undies and run about in public this time around), but not particularly endearing. It’s not exactly a one-note performance, but unlike Thompson’s it’s lacking it shading and undercurrents, and it grows tedious over the long haul. Gyllenhaal is pretty much wasted in a part that requires nothing but generalized spunk, and Latifah is forced to be so well behaved that she’s simply dull, something that can’t usually be said of her. Though Hunt’s given little to do in her single scene, Tom Hulce turns in an amusing cameo as a with-it IRS counselor.

“Stranger Than Fiction” isn’t unpleasant to sit through, but watching it one gets the feeling that the makers were trying to feed into a trend of oddball surrealism, most closely associated with Kaufman, that’s already gotten trite from overuse. So their picture feels less like a story you find clever and surprising than like a book you’ve read before. Far from being strange, it’s the sort of movie that’s become too familiar to make much of an impact or offer much enjoyment.