"The reunion's bombing!" wails a distraught hostess about half an hour into the dreadful procession of inane, mirthless gags that constitutes "National Lampoon's Class Reunion." Unable to escape the self-incriminating nature of this remark, the movie goes on bombing with obstinate consistency for another wasted, misplaced hour or so.

"Class Reunion" begins with a prologue set 10 years ago, when members of the 1972 graduating class at apocryphal Lizzie Borden High conspire in a nasty practical joke at the expense of feebleminded Walter Baylor (Blackie Dammett). While the scene ends before the precise nature of the betrayal is revealed (predictably, it turns out to be a groaner when ultimately specified), poor Walter is presumably humiliated into enough of a vengeful state to return 10 years later and terrorize his tormentors at the class reunion.

Given the untapped satiric possibilities, it's difficult to see what screenwriter John Hughes and director Michael Miller thought they gained by spoofing a horror movie rather than the authentic ways in which a reunion tends to inspire wacky interaction. Hughes carved a distinctive humorous niche at the National Lampoon in the late '70s, but apart from the obvious dope jokes allotted to the class potheads, Chip and Carl (Barry Diamond and Art Evans, a mildly amusing team of stooges), now so addicted that their brains are beyond recall, there's little indication of a comic outlook intimately associated with memories of the '70s.

The setting itself is transparently absurd -- the celebrants return to a shuttered, condemned Borden High that looks like a haunted mansion and has evidently been crumbling away for the better part of 10 years -- but this conceit never looks pictorially witty or outrageously believable.

In addition, the filmmakers keep failing to familiarize you with a basic cast of characters and then to sustain individual scenes from downbeat to comic payoff. As a rule, most of the types introduced (Gerrit Graham as a snobbish preppie, Shelley Smith as a glamor girl, "Animal House" alum Stephen Furst as a horny slob, Miriam Flynn and Marla Pennington as class bitches, Randolph Powell and Misty Rowe as impulsive adulterers and Gary Hibbard and Isabel West as their oblivious spouses) tend to get lost in the shuffle of raggedly staged and abruptly terminated scenes. Almost every episode seems to end before concluding its presumed comic business. Even a brief guest spot by Chuck Berry is treated so negligently that five minutes later you feel doubtful about having seen him.

There are a handful of effective gags, mostly of the sick and/or sophomoric persuasion: Anne Ramsey as a slovenly old cafeteria hand, Mrs. Tabazooski, loading up the guests' plates with her bare, filthy hands; a seeing-eye dog devouring the Tabazooski repast carried, precariously, by its mistress; the discovery of a cherished erotic relic, a coed's sweater prominently imprinted with the owner's bustline.

No doubt there's enough misused and shortchanged talent in the cast to supply another "American Graffiti" or "Animal House," but "Class Reunion" is a credit they'll be obliged to overcome.

Against considerable odds, Fred McCarren manages to seem fitfully ingratiating in the role of the nominal hero, a sweet-tempered doormat called Gary Nash, while Marya Small and Zane Busby (the unforgettable cleanser snorter from "Up in Smoke") transcend the grotesque excesses of assignments as class crips. Ramsey, Furst, Diamond and Evans, Steve Tracy as the murder victim and Michael Lerner as an ambiguous psychologist also contribute bits that might have gone further in a less stunted comedic context.