"The Survivors," a dithering, disheveled attempt at outrageous and scornful satire, will be fortunate to survive the wreckage of its structural and thematic collapses. Opening today at area theaters, this peculiarly messy, self-defeating entertainment is subject to so many calamitous cave-ins that it might be appropriate to pass out hardhats to the customers.

"The Survivors" never gets any of its potentially amusing notions and resources in effective proportion, beginning with the costarring team of Robin Williams and Walter Matthau. Williams and Matthau are cast as two hard-luck New Yorkers thrown together by a ludicrous pattern of adversity that leads to a laborious runaround of a slapstick showdown at a winter camp for trigger-happy survivalists.

Director Michael Ritchie seems to have misplaced the flair for social comedy that distinguished earlier credits like "Smile" and "The Bad News Bears." This effort--with screenwriter Michael Leeson, making his movie debut after a successful TV apprenticeship with "Taxi"--lurches around in desperate need of a coherent humorous tone, attitude and plot.

Although the survivalists, a para-military group of suckers eagerly anticipating the end of civilization, emerge as a target of sloppily contrived ridicule, the script betrays a maddening ineptitude at rationalizing the events that bring the principal characters together initially and then deciding what it is that keeps them comically entangled.

The early episodes suggest a farce conceived for the recession winter of 1981-82. The Williams character, Donald Quinnelle, learns he's been fired one morning when he reports for work at the executive offices of (I think) a dental equipment supply company. Stunned, he stops for gas and absentmindedly causes a fire that destroys the station, owned by Matthau's character, Sonny Paluso.

With their livelihoods suddenly eliminated, Donald and Sonny are shown experiencing hard times of a predictably hostile, humorously uninspired kind at the unemployment office.

The plot eventually wends its way to a snowbound survivalist retreat, but not before Jerry Reed is introduced as a hit man stalking Donald and Sonny.

Williams and Matthau promise a funny, hare-and-tortoise contrast of personalities and styles, but Ritchie ends up ruinously dependent on Williams for keeping a sinking vehicle afloat with frenzied mugging and ad-libbing, or what most viewers will naturally assume to be ad-libbing.

After all, it echoes Williams' uninhibited standup material and reflects a knowing, deliberately facetious outlook that destroys the vestigial credibility of the fanatic stupe he's supposed to be playing. Fundamentally, Donald is a dummy and the performer's irrepressible inventiveness can't rationalize turning him into a dummy capable of undisguised snappers, like the parody of Robert Duvall in "Apocalypse Now" when Donald gazes at his huskies and exults, "I love the smell of Malamute in the morning!"

Matthau remains the stabilizing, rational component of what might have been a memorable new odd couple, but the material isn't calculated to rely on the steadying, civilizing, comic influence of his sanity and irony. If anything, "The Survivors" ought to soft-pedal Williams' manic antics and enhance Matthau's role as a voice of reason.

As a matter of fact, Matthau is technically better at certain kinds of comedy shtick than Williams--for example, compare the richness of his snoring noises with the relative banality of Williams' involuntary moaning. There are bits that require a lifetime of practice to perfect.

The fresh comic performer in the film is Annie McEnroe, as Donald's preppie fiance' Doreen. She gets marvelous effects from a soft voice and a mouth often set in a straight, horizontal line. In her single sustained scene, she makes Doreen so ingratiating that Donald seems even dumber for preferring survivalist camp to her company.

The movie manipulates its devices so clumsily that the last thing the filmmakers could reasonably expect was to earn brownie points for the integrity of their liberal social consciousness.

Screenwriter Leeson gives a subsidiary character, Kristen Vigard as Matthau's teen-age daughter, a line that nicely sums up the antisocial folly of Donald and his comrades: "Aren't you guys gonna get really bored if society doesn't collapse?" It's a nifty line, but it's lost in such a dilapidated context.