I've never seen a heroic spectacle as ostentatiously stupid as "Conan the Barbarian."

A hulking, indomitable warrior-adventurer, Conan is located in a semi-Teutonic, semi-Oriental never-never land of tribal antiquity. The film's production designer, the noted illustrator Ron Cobb, imagines Conan's stomping grounds as a delirium of landscapes from old movies--"The Vikings" crossed with "Marco Polo" crossed with "The Thief of Baghdad" crossed with "Lost Horizon" crossed with "Hercules" crossed with "Seven Samurai."

One of several neolithic superheroes created by an obscure pulp writer named Robert E. Howard, Conan was introduced in a 1934 issue of the monthly Weird Tales. Howard completed 18 Movies Conan stories before putting a bullet through his head in 1936. Evidently, the character--and his imaginary epoch, which Howard called the Hyborean age--did not begin to make a big impression on a susceptible juvenile reading public until 1966, when Frank Frazetta illustrated a paperback reprint.

The image of awesome, hyperbolic muscularity imposed by Frazetta is also meant to dominate the movie version, where it's transformed into unintentional nonsense, thanks to the unfailing cloddishness of director John Milius and his all too trusting star, champion body builder Arnold Schwarzenegger.

Mad magazine is certain to have a high time exaggerating Schwarzenegger's limited but reliably hilarious range of expressions in the role of Conan. I think I prefer his pensive frown to his peevish scowl, but it's a close call. The nonstop goofiness of the plot should also be an irresistible challenge to Mad humorists, who may improve it considerably by condensing the episodic, occult clutter and dragginess of the Milius-Oliver Stone scenario into a handful of salient gags.

"Conan" is overproduced to the verge of sluggishness. It's heavier going than "King Kong," "Orca," "The White Buffalo" and "Flash Gordon" put together, if you can imagine such a punishment. While it looks and sounds consistently absurd, the film is too grandiose and solemn to capitalize on the enjoyable aspects of its fundamental absurdity.

Cobb's mock-primitive exoticism fails to conceal the triteness of the story, the saga of an orphaned, enslaved youth who matures into a superman and exacts revenge on the fiend who slaughtered his parents.

The pompous narration promises a system of illusion that Milius can never sustain: "There was an age undreamed of . . . let me tell you of the days of high adventure . . . once giants lived in the earth . . ." This balderdash may stir Milius, but he can't bring a farfetched Heroic Age to dynamic, satisfying life on the screen. If anything, he needs remedial instruction in most aspects of his craft.

"Conan" is a technical shambles in such crucial departments as dramatic continuity, sound recording, editing, acting. Unless you've studied the Conan mythology religiously, the chronicle of adversity, adventure and ultimate triumph depicted by Milius is almost certain to appear opaque.

What seems to blunder across the screen is not so much a coherent heroic legend as a collection of savagely cuckoo blackout sketches. Certain motifs and payoffs seem to repeat themselves, but they're too vicious on one hand or ridiculous on the other to prove rewarding. Images of decapitation become a catchy motif.

There's also a lot of Schwarzenegger striking poses with a huge sword clutched in his paws and Schwarzenegger yoked to various torture devices. Lusty tribal wenches go up in phosphorescent sparkles every so often, a fireworks display that suggests the Hyborean female was rich in phosphorous. As the leader of a murderous cult, James Earl Jones glowers from beneath a voodoo fright wig that actually makes him look frightfully matronly. He also seems addicted to snuffing captive white women, the least ingratiating kink of the season.

Although the cast contributes a melting pot of accents, the mushy recording makes everyone equally difficult to decipher. The need to utter an occasional remark is keenly disillusioning in Schwarzenegger's case. Milius aggravates the problem by timing Conan's very first utterance to coincide with his period of apprenticeship under a Japanese martial arts master. Inevitably, we are left with the impression that this Japanese guy is somehow responsible for Conan's funny Austrian accent.

There's not a single effectively visualized action sequence in the movie. For some reason the imagery is never expressively concentrated during scenes of combat, rather a big deal in this sort of adventure fantasy. The camera is habitually out of position in the heat of battle. Compatibly uncoordinated, the cutting seems to switch angles either too soon or too late. You'd think that the law of averages would produce a sharply composed or timed sequence now and then, but each time Milius sets up an action spectacle, it looks blurred and anticlimactic.

Obviously, Schwarzenegger has been left in the most exposed position by the overreaching incompetence of the director: He's the oversized patsy at the center of a blockheaded fantasy. If it's any comfort, nobody comes out of this pagan costume farce looking fashionable. As the warrior heroine Valeria, for example, the athletically streamlined dancer Sandahl Bergman is photographed in such a coarse, unflattering way that she appears weirdly mannish--just one of the louts, but with breasts.

You don't expect the relative amateurs like Schwarzenegger and Bergman to know enough to protect themselves from booby-trapped roles. You do expect more sanity from an old pro like Jones, who nevertheless seems determined to ham it up as the reptilian villain, Thulsa Doom. Poor Schwarzenegger can't help looking silly, but what gives with Jones? Perhaps dubbing the voice of Darth Vader made him itchy for a villainous fling in the flesh. In "Conan" he lets his hair down with a humiliating vengeance: Thulsa Doom is Darth Vader in hag drag.