Don't expect to see "The Adventures of Buckaroo Banzai: Across the 8th Dimension" just once and be able to make sense of it. You'll probably enjoy it, maybe even love it, but you're not going to get the Big Picture until you've put at least two or three notches on your popcorn box.

It's good box-office strategy, of course, and first-time director W.D. Richter and writer Earl Mac Rauch have compounded it by throwing in a little bit of every cinematic genre (except ultra-gore) to the point that "Buckaroo Banzai" becomes the ultimate hyphenate: a comedy-sci-fi-Zen-western-adventure-rock-thriller. The surprising thing is that it works.

But so will you. At least when George Lucas set you down in the middle of a galaxy far, far away he stepped back from time to time to explain, to clarify, to prepare. No such thing happens here: It's full thrust from frame one to the promise of more to come at the end.

Drawn from sources as disparate as B-films and serials, pulp novels, comics and '50s television, and stocked by hardware that owes more to Popular Science than MIT, "Buckaroo Banzai" doesn't so much progress as unravel, but it does so in such a raucously ingenious and good-natured manner that one hardly cares. Having concocted a scenario so densely layered that at film's end you're looking for a concordance rather than a credit list, Richter and Rauch don't ever look back. Since their art obviously belongs to dada, you may be excused your confusions.

It's obvious that Richter and Rauch found themselves unable to throw out any of the ideas that flitted through their overactive minds in the nine years it took to get "Banzai" to the screen. It's busy, but to paraphrase one of the Zen lines in the movie, "no matter where it goes, there you are."

En route, Richter and Rauch have created a cool, enigmatic anti-hero for the mid-'80s, one who will reflect just about anything audiences are willing to read into him. This time around, he's called Buckaroo Banzai, a neurosurgeon/race car driver/physicist/guitarist (in no particular order) and a scholar-hero who makes Indiana Jones look like nerd-meister Rick Moranis.

Banzai is unflappable, sensitive, mystical and handsome (actor Peter Weller looks like a sharpened Rick Springfield) and, like Doc Savage or Robin Hood, he's surrounded by a magnificent band of merry men who go under the colors of Team Banzai: call them the More than Magnificent Seven. When they're not saving the world from aliens or engaging in scientific breakthroughs, they play rock in seedy New Jersey bars as the Hong Kong Cavaliers.

The plot goes something like this: first, it turns out that the Orson Welles "War of the Worlds" hoax way back in 1938 was not a hoax, but a beginning. When Buckaroo's Jet Car drives straight through a mountain thanks to his newly invented Oscillation Overthruster, it proves the existence of the 8th Dimension; unfortunately, it also unlooses the Red Lectroids from Planet 10 (half-lobster, half-lizard, they are all klutz).

Meanwhile, Dr. Emilio Lizardo (John Lithgow), having juiced himself up via self-sustained electric shock therapy, has escaped from a home for the criminally insane and revealed himself as the knavish John Whorfin. He's trying to get the overthruster from Banzai, who's been given a stop-them-or-we'll-blow-up-the-world ultimatum by the good Black Lectroids (disguised as, and speaking elliptically like, your average dreadlocked Rastafarians). Then there's the matter of Buckaroo's ex-wife's long-lost twin sister, Penny Priddy (Ellen Barkin); the secret spaceship being built in the bowels of Yoyodyne Propulsion Systems and the organic one floating through the sky; a presidential security adviser named Smirnoff and his "Declaration of War: The Short Form"; dozens of Red Lectroids surnamed John who can't spell; and . . .

Well, it's a mindfull, all right. And if it's hard enough to make good sense, it's even harder to make good nonsense, which is exactly what Richter and Rauch have done. It helps that there is a stellar madman's performance from John Lithgow, one that makes his terrified passenger in "The Twilight Zone" seem positively sedated. It helps that the Lectroids are delightfully evil. It helps that Jeff Goldblum is irreconcilably different as the nice Jewish doctor who joins the cosmic cowboys dressed for the dude ranch.

Other things add up, as well, from Fred Koenekamp's hazy cinematography to the underplayed special effects by Michael Fink to Michael Riva's production designs, which opt for high camp where high tech might have obscured the lunacy. "Buckaroo Banzai" benefits from its incessant business, a lack of which seemed to doom "Strange Invaders," last year's exquisite sci-fi sendup. As American in its humor as Monty Python is British in its, "Buckaroo Banzai" is fantastic in a funny kind of way, a futuristic tour-de-force that leaves you laughing and anticipating the sequel.