If ever there were a one-trick pony, "Nacho Libre" is it. There's just a single joke here, and that's Jack Black's turn as the titular orphan who was raised in a Mexican monastery and now serves meals of stale chips and slop masquerading as refried beans while harboring dreams of stardom as a luchador. In order to buy better groceries for the orphans and impress a new teacher, Sister Encarnacion (Ana de la Reguera), he teams up with skinny straight man Esqueleto (Hector Jimenez), fashions a fey sky-blue Superman costume and steps into the square circle. The final touch is the sport's signature mask, which has the added advantage of also disguising a not-always-convincing body double during the wrestling matches. But Black's performance is only funny enough to sustain, say, a three-minute trailer.

Although one is hesitant to sentence "Napoleon Dynamite" writer/director Jared Hess to one-hit wonder-dom just yet, this follow-up to that absurdist sleeper bears a passing resemblance to its predecessor: At its center is a geeky--worse, nerdy--misfit with aspirations for the extraordinary who toodles around on a ridiculous contraption with yet another droll Mexican in tow. "Napoleon" was rated PG, too, but somehow it didn't feel like it, or at least didn't feel like it had been hobbled to achieve it, as this Black vehicle, notably produced by kid-friendly Nickelodeon Movies, does. Slightly risque moments involving crotch-grabbing and open-to-interpretation declarations of "I need a man" have been so carefully choreographed as to lose any double meaning, and Black's much-touted signature Lucha Libre move, "The Wind of the Lion," although mentioned in the press notes and elsewhere, fails to make an appearance in the movie.

On a positive note, the production aimed for authenticity by shooting entirely on-location in Oaxaca, Mexico, with a local crew and largely Mexican cast. Starring Jack Black, Ana de la Reguera and Hector Jimenez. Directed by Jared Hess. Written by Jared Hess, Jerusha Hess and Mike White. Produced by Mike White, Jack Black, Julia Pistor and David Klawans. A Paramount release. Comedy. Rated PG for some rough action and crude humor including dialogue. Running time: 98 min