THE BIG BRAWL -- At 13 area theaters.

THE OCTAGON -- At 23 area theaters.

It had to happen: preppie king fu.

No sinister black jumpsuits for Jackie Chan. With his knitted sweater vests, pleated pants and squeaky-clean haircut, the hero of "The Big Brawl" looks like he wandered off a college campus. And while other kung fu stars snarl their way from fight to fight, Chan is all smiles. For those who've received their martial-arts education at the hands of Bruce Lee and his assorted clones, it's all a bit disconcerting.

Needless to say, "The Big Brawl" is not your average kung fu movie: Kung fun would be a better name for it. Chan, drawing on his experience as a member of the Chinese Opera, displays a sense of comic timing that's as accurate and well-developed as his acrobatic abilities. In his own entirely different way, he's a charismatic as Lee ever was.

Chan's training in mime, theater, gymnastics and the martial arts is evident from the start, when he takes on a trio of Mafia goons with witty, self-depreciating style.

As with most action films, the story line is a little thin. The scene is Chicago, 1980, so everybody gets to run around in funky '30s clothes. Chan plays the cheerful, Americanized son of a Chinese-born restauranteur who is being victimized by the local Mafia boss. He ends up having to go to Texas to compete in a "Brawl of the Century," or his brother's mail-order bride will be killed. It doesn't make a lot of sense but then, they never do.

What it does is provide a showcase for Chan's martial-arts skills -- and those of Mako, the balding, dapper gent who plays his exacting trainer. ("Sometimes you make me tremble with disgust," is the old man's considered opinion after Chan's turned in what looks like a flawless routine.) In addition, Jose Ferrer's Grandoesque portrayal of the Mafia don is always amusing, and Kristine DeBell is low-key perky as Chan's girlfriend. It's a treat, in a movie like this, to get such appealing supporting characters.

It seems almost unfair to compare Chan with another maritial-arts star, Chuck Norris, whose film "The Octagon" opened here last week. There are some surface similarities: Norris is clean-cut too, and he's also irresitible to women. But in his case the appeal is inexplicable.

There's nothing subtle, either, about Norris' brand of martial arts. This is serious macho business all the way. By the end of the movie, when Norris has killed off an assortment of terrorists and mercenaries, the mood is decidely grim. Norris has all of Chan's agility -- but none of his flair.