Grade: C-

Mark Twain’s “A Connecticut Yankee in King Arthur’s Court” is not a work that’s traditionally been treated very respectfully in translation to the screen. Certainly neither the 1931 adaptation, refashioned for Will Rogers, nor the 1949 version, which turned the piece into a musical vehicle for Bing Crosby, could be termed faithful. A 1989 TV version, moreover, transformed the out- of-time visitor into an urchin played by Keshia Knight Pulliam, while a 1995 French-Canadian- British co-production, retitled “A Young Connecticut Yankee in King Arthur’s Court,” featured an otherwise unknown Philippe Ross in the title role. So the fact that it’s been even more strenuously reshaped to spotlight Matthew Lawrence should not be a cause of serious complaint. What one might object to, though, is that the result, while a mere ninety minutes long, runs out of invention long before it lumbers to a close. “Black Knight” is a decidedly thin, anemic farce.

The set-up, obviously derived from Twain but with the Camelot setting excised, is as obvious as they come. Lawrence plays Jamal Walker, a flippant L.A. hustler who works at a locally-run medieval theme park threatened by a franchise rival; a fellow devoid of loyalty, he’d rather switch than fight. Soon, however, he’s magically transported to 1328 England, where–in utter violation of historical fact, but who cares?–he finds himself mistaken for a messenger from the Duke of Normandy to King Leo (Kevin Conway), a usurper who, with the help of mean knight Percival (Vincent Regan), has deposed a beloved queen (Helen Carey). Before long Jamal, renamed Skywalker for some reason, is acting the part of royal jester and teaching the court to dance hip-hop style, while getting involved in a rebellion to restore the crown to its rightful holder–a plot that includes his romantic interest, lady-in-waiting Victoria (Marsha Thomason) as well as over-the-hill Sir Knolte (Tom Wilkinson). One part of the venture eventually involves the legend of the Black Knight, here depicted as a sort of chivalric Robin Hood, whom Jamal rather implausibly impersonates to shift the tide of battle. And when our hero finally gets back to his own time, he helps to save the park at which he works, having learned the lesson of responsibility to one’s local community–as well as stumbling upon Victoria’s contemporary equivalent, of course (can reincarnation be at work?).

This is awfully feeble stuff, and it’s been constructed as a virtual stand-up set for Lawrence (who’s also the executive producer). There’s nothing terribly wrong with this–after all, one can still get modest amusement from the similarly star-centered period farces concocted for people like Bob Hope and Danny Kate in the forties and fifties–but unless you’re really addicted to Martin’s brand of mugging and goofy slapstick, you’re unlikely to be delighted by it over the long haul; the writers simply don’t invent enough set pieces for him to shine in. (When the script descends to the apparently obligatory, sadly predictable device of resuscitating a dead character at the close, it goes beyond the pale.) Certainly the other performers get virtually nothing to do, apart from Regan, who overdoes things horribly as the snarling Percival, and Wilkinson, a distinguished actor (brilliant in the upcoming “In the Bedroom”) who wisely hides beneath a beard and tries to underplay Sir Knolte in an apparent, and nearly successful, attempt to render himself unrecognizable. The flaccid direction by Gil Junger (who did far better in his feature debut, “10 Things I Hate About You”) imposes no discipline on Lawrence, with the result that most of the episodes are mercilessly labored and overextended; and the entire production has a chintzy, threadbare look.

If you want to see a black knight, it’s probably still best to savor the exquisite villainy that James Mason brought to the role the woozily hilarious “Prince Valiant” back in 1954, rather than either the stalwart heroism Alan Ladd showed as the eponymous figure in a juvenile British adventure of the same year or Lawrence’s shrill bumbling here. Against formidable competition from the likes of Harry Potter, this “Knight” won’t remain in the cinematic saddle for long.