Hollywood was relatively easy to figure out in the early '60s, according to screenwriter George Axelrod. Three kinds of movies were permissible: musicals, Westerns and "different." The only way you could outsmart yourself was by making something so different that it fell into a troublesome fourth category -- "different different."

Richard Rush's production of "The Stunt Man," opening today at the Jenifer, may be remembered as the classic example of "different different" to survive the Hollywood of the '70s. Flawed and uneven, but vigorous and imaginative, "The Stunt Man" is a brash, whirlwind action comedy about the paranoid uncertainties of a fugitive who takes refuge with a movie company on location.

The film invites us to participate in games of deception that unfold in a setting where the creation of illusions is everybody's business. But what sort of business?

Based on Paul Brodeur's 1970 novel, "The Stunt Man" suggests that human fate is similar to the predicament of its puzzled protagonist, who endeavors to save himself by performing dangerous stunts for an all-powerful director whose purposes remain ambiguous. Is the stunt man a pawn of a benevolent or diabolical despot?

The panicky, ignorant young fugitive, played with compelling intensity by Steve Railback (best known for a sensational impersonation of Charles Manson in the TV movie "Helter Skelter"), carries over the symbolic name of Cameron, as in "camera on," from the novel. During an intricate, clue-strewn opening sequence, Cameron bolts as two policemen attempt to arrest him in a cafe. The reasons for his flight remain a mystery until he finally unburdens himself in the most remarkable and enjoyable "revelation" scene committed to celluloid in a long time.

Cameron blunders into a situation that implicates him in the death of a movie stunt man. He soon ends up impersonating the dead man, pressed into emergency service by the film's flamboyant, cunning director, Eli Cross (Peter O'Toole in a tour de force caricature of the filmmaker as grandiloquent con artist), who hopes to conceal the death in order to avoid a police investigation that might interfere with the production.

Cross also has an ulterior artistic motive for exploiting Cameron. He senses that the fugitive's real desperation may provide an interesting emotional undercurrent, "an authentic stench of madness beneath all the good clean fun," as he puts it to his long-suffering screenwriter Sam, played by Allen Goorwitz. The ironies are irresistibly tempting: Cameron will be posing as a stunt man doubling for an actor playing a World War I American aviator posing as a fugitive German soldier in a mind-boggling action epic that appears to be a cross between "the Blue Max" and "King of Hearts."

Cross' authority is sufficient to protect Cameron for exposure, and Cameron becomes the grateful, willing pupil of both Cross and stunt supervisor Chuck Barton (the veteran stunt man Chuck Bail, who served as Rush's second unit director). He also excites the possibly sincere, possibly treacherous interest of the leading lady, Nina Franklin, played by Barbara Hershey.

Caught up in the shooting and his passion for Nina, Cameron feels an elation tht soon gives way to aprehension. From his dependent, jumpy perspective, he can't tell whether he's being protected during the stunt sequences or just lucky to get out alive. Finally, Cameron becomes convinced that Cross means to sacrifice him by reshooting the stunt that cost the life of the original stunt man.

Rush's system of illusion is not exactly foolproof. Certain virtuoso touches, like the depiction of complicated stunt work in long continuous takes that would be virtually impossible in reality, may even boomerang and interfere with a willing suspension of disbelief. Instead of obscuring the repetitious, monotonous aspects of the filmmaking process, I wish Rush had devised a more convincing trick of perception, perhaps by beginning with the stunts as staged and ending with them as assembled by a film editor.

If we felt Cameron were a more sophisticated or perceptive character, his delusions would be unacceptable. Since the movie keeps switching perspectives -- sometimes identifying with Cameron's limited outlook and sometimes communing with Cross, the man who presumably commands the overview (literally a deus ex machina, he keeps making lofty comic entrances by helicopter or camera crane) -- it would be difficult to play along with the naivete' if Railsback were a less vigilant actor.

Cameron also seems peculiarly humorless to miss the reassuring hints, which are almost invariably comic. Cross articulates the first rational warning. In the opening sequence a buzzard flies near the window of his helicopter, provoking the pilot to exclaim, "That bird tried to kill us!" Taking the comprehensive view, Cross replies, "That's your point of view. Ever think to ask the bird what he thought?" On the set Cross frequently reminds his performers, Cameron included, "King Kong was only 3 feet, 6 inches tall. He came up to Fay Wray's navel."

At the same time, there's no doubt that Cross does deceive and manipulate. One of the most persuasive inside-moviemaking details shows him deliberately exposing Nina to embarrassment in order to coerce a certain reaction from her in an upcoming scene. The question is, how far is he prepared to go to achieve the effects he wants?

"The Stunt Man" is likely to achieve a durably popular place among the tradition of movies about the movies. Maybe not at the very top of the list, with pictures like "Sunset Boulevard" and "Singin' in the Rain," but certainly among the fascinating runners-up like "Sullivan's Travels," "Day for Night" and "8 1/2."

Ultimately, what distinguishes this hit-and-miss rouser from other movies is that it succeeds in using the movies as a metaphor without making a pretentious intellectual nuisance of itself. There are times when you wish Richard Bush were a more subtle director, but on the whole it's preferable that Brodeur's literary conceits ended up being transformed by a more down-to-earth, vulgar sensibility. As Eli Cross reminds us, "Reality can be pretty outrageous."