Off Broadway first-nighters have lately been attending a succession of ''how to'' seminars in dramatic form. The general course heading might be: Human Predicaments and How to Solve Them. Solutions offered at these group encounter sessions have ranged from the sentimental to the drastic and bizarre.
The learning experiences proved enlightening and (equally important) entertaining. How much so has depended on the quality of the works in question, the receptivity of the playgoers, and even the relationship between the admission price and the instruction received. In any case, there is no questioning the authors' thoughtful concern about the human dilemmas with which they have been dealing.
Two of the works under consideration here are by playwrighting veterans - David Mamet and John Ford Noonan. Although only Mr. Mamet has been represented on Broadway (beginning in 1977 with ''American Buffalo''), both he and Mr. Noonan have enjoyed extensive success Off Broadway and in resident professional theaters beyond New York. As for newcomer James Edward Luczak, his ''Some Rain'' was among the works to emerge last summer from the refining process of the National Playwrights Conference at the prestigious Eugene O'Neill Memorial Theater Center in Connecticut. 'Some Men Need Help'
Mr. Noonan has written a contemporary, odd-ball version of the Good Samaritan parable. His samaritan is Gaetano Altobelli (Philip Bosco), a rich, big-hearted Italian-American with an evident criminal past. Gaetano endures insults, assaults, and contempt to rescue Hudley T. Singleton III (Treat Williams), the meanest WASP in Fairfield County, Conn.
Hud, as Gaetano cheerfully insists on calling him, has not fallen among thieves and been left half-dead. Instead, after bitterly realizing how far his career achievements have fallen short of expectations, the disillusioned ad man has driven his wife from home and now seems intent on drinking himself to death.
The Noonan approach to Gaetano's rescue mission is as antic as it is serious. Armed with the kind of curriculum vitae about Hud that only a guardian angel could possess, Gaetano launches his campaign. He takes command, moves in, and begins the job of transforming the object of his solicitude into a decent human being.
While ''Some Men Need Help'' strains credibility at times, the performance staged by John Ferraro endows it with a kind of make-believe believability. The jauntiness and persistance of Mr. Bosco's Altobelli is matched by the skill with which Mr. Williams portrays Hud's transformation from hateful self-destructiveness to dawning goodwill and affection.
Whatever its imperfections and limitations, ''Some Men Need Help,'' at the 47 th Street Theater, practices what it preaches by pursuing a compassionately upbeat theme. 'Edmond'
David Mamet's new play at the Provincetown Playhouse bears at least a lateral resemblance to ''Some Men Need Help'' - and not just because of the help the titular hero of ''Edmond'' so desperately needs. In its own far more corrosive way, the Mamet phantasmagoria starts from a premise of bourgeois malaise. And on his own very debatable terms, Mr. Mamet imagines a ''happy'' ending for his urban Everyman.
''Edmond'' is a brutely surreal allegory about the hate, prejudice, violence, and sexual aggression that imperils human relations and threatens the fabric of human society. The hero is a middle-aged New Yorker who abruptly abandons his wife of many years. He then embarks on a nightmare ordeal of midtown lower-depths experiences that lead to his imprisonment for murder and his sexual submission to a towering black cell mate.
This pilgrim's progress through hell unfolds in Mr. Mamet's characteristic blend of rhythmic, often staccato exchanges and veristic colloquialism (with no obscenities deleted). The writing is as controlled as the hero's behavior is wildly impulsive. Colin Stinton's Edmond is a precise study of an uneasy, middle-class racist who's threat to others begins with his own self-destructiveness. Edmond is also astonishingly naive and obtuse.
There is no doubting Mr. Mamet's concern or seriousness of purpose. Considering what has gone before, however, the notion that Edmond finds redemption and release in a homosexual relationship with his violator seems, at the least, simplistically contrived and incredible. 'Some Rain'
Sara (Blanche Cholet), the waitress-heroine of ''Some Rain,'' faces the common predicament of those who feel that life has passed by without their leaving any impression on it. Into Sara's drab existence and the untidiness of her trailer-home comes Wally (Loren Haynes), a handsome and amiable drifter.
Wally tidies up the place, is invited to spend the night, and disappears the next morning. No sooner has Wally taken off than Sara is visited by Eddie (David Dawson), her longtime boss, an admirer who has never before spoken his heart. Playwright Luczak rewards his patient waitress-in-waiting with something more than a mere consolation prize.
The frail little romantic drama at the Lion Theater includes more than its share of cliches - the road-side diner bypassed by the new state highway, the approaching storm, the arid garden patch that suddenly blossoms, etc. ''Some Rain'' also is haunted by echoes of other plays. But the brief two-acter does exhibit a decent respect for its trio of average Americans and for the human condition in general. The cast directed by Dale Rose responds appreciatively to these humane concerns.