If you feel moved to applaud at the end of "Brubaker," don't bother. Someone, presumably the talented young screenwriter W. D. Richter, working with relentless kneejerk facility, has seen fit to write it into the story -- a vivid, entertaining and shamelessly manipulative "crusading" melodrama about the impact of a reform warden on a barbarous penal institution. m

The hardened inmates of Wakefield Prison Farm, a den of corruption and exploitation situated Somewhere Down South (the locale was an abandoned prison outside Cleveland), gather to salute the departing crusader, warden Henry Brubaker.

He is embodied by a virtuous presence named Robert Redford, whose priggish aura of righteousness and moral superiority was perhaps as unintentional as it is irrevocable and unfortunate. Brubaker's Stubborn Refusal To Compromise has cost him his post and the opportunity to go on improving conditions at Wakefield, where conditions are worse than you remember from "I Am a Fugitive From a Chain Gang."

Brubaker, a bit of a grandstander, takes his leave while the incoming warden is making his introductory speech to the assembled throng. The inmates -- led by a black convit trusty (played by Yaphet Kotto) who has learned to trust and respect at least one white man -- ignore the new chief to hail their short-lived champion, who may have blown it for them if you look at things a trifle cynically.

Nevertheless, Wakefield had its touch of Camelot. Brubaker's car pulls away and the camera ascends to a lofty panoramic vantage point, implying . . . I dunno, but it's difficult to shake the impression that heaven has duly noted Brubaker's heroic effort and has given him an "A." This built-in note of approval seems perfectly appropriate to a movie as slanted as "Brubaker." It never wastes a second agonizing over subtleties.

Although Richter's screenplay leaves certain large areas unexplored or unexplained -- including Brubaker's own psychological makeup and the precise linkage between the groups inside and outside Wakefield that have a vested interest in resisting reform -- there's not a bit of slack in the picture.

Every scene has incisive or portentous definition, the boldness of a color comic book. The effect is reinforced by director Stuart Rosenberg, who hasn't functioned with such blunt effectiveness since "Cool Hand Luke" 13 years ago, and by the splendid European cinematographer Bruno Nuytten ("Going Places" and "The Best Way to Get Ahead"), whose pictorial schemes seem to rely on lenses and lighting that endow the performers with hard-edged immediacy.

The flesh tones and facial contours seem shockingly prominent. Literally, everything meets the eye. Characters are what they seem to be at first glance; sadists and chiselers and hypocrites in most of the positions of authority, brutalizing helpless or defiantly tough cons until the intervention of the noble warden briefly disrupts the sordid and degrading practices.

This melodramatic definition is one reason why you may resist the premise of the opening reel, which finds Brubaker posing as a new inmate in order to see the horrors of Wakefield at firsthand. Redford sticks out like an angel at an orgy, and Brubaker seems downright foolhardy putting his life in jeopardy in the interests of what would have to be strictly corroborating research.

I gather that Brubaker's imposture is one of Richter's inventions rather than an authentic aspect of the real-life conflict the movie is based upon: the experiences of Thomas Murton, who had a brief, controversial tenure as director of the Arkansas prison system in the late '60s.

"Brubaker" appears to invent the investigative penologist. While the undercover episodes are brutally effective and perhaps necessary as appalling documentation, Redford's presence as an eyewitness never ceases to feel far-fetched. It's a relief when he finally unmasks -- and a wonder that he's survived.

In all justice, the position of applauder and applaudee at the fadeout should be reversed. Redford's Aryan beauty plays havoc with what is obviously meant to be a sincere, modest performance. It's the supporting cast that deserves congratulations, Kotto, David Keith, Tim McIntire, Everett McGill, Richard Ward, Morgan Freeman, Matt Clark, M. Emmet Walsh, Joe Spinell and many others contribute to a scintillating lineup of cons, guards and bureaucrats. Keith, playing a fearless, humorous, gallant young tough, is perhaps the most impressive of the inmates. McGill, a tall, rawboned, brooding menace who recalls Jack Palance threatening the homesteaders in "Shane," is clearly the class of the sadists.

The class of the bureaucrats happens to be a token female: Jane Alexander as the governor's aide who fronts for Brubaker and urges him to make all those astute political compromises he cannot find it in his noble hide to make. Although her criticisms of his self-righteous moralism sound welcome and Alexander makes a winning spokeswoman for Taking the Long View and Struggling Within the System, the filmmakers seem to introduce her arguments solely for the sake of argument. Ultimately, she's brushed off and Brubaker's virtue is celebrated without serious qualification. b

There's also a token slut: Linda Haynes as a woman who shares dirty pleasure with guard McIntire, whose lustful activism is an index to his depravity.

The warden is so chaste and preoccupied he doesn't even show a glimmer of sexual interest in his patron, although Alexander projects a few suggestions in the opposite direction. In the weirdest episode of the film, a grief-stricken Redford gives himself a zap with the generator that has been used to torture inmate Richard Ward and then left brazenly on the warden's desk.

Come again? There must be more to Brubaker than meets the eye, but where did this touch of kink come from? If we rummaged around the wardens colset, would hidden porn books and biographies of Lawrence of Arabia come tumbling out?