Traditionally, the Kennedy Center's American College Theatre Festival has been so thoroughly drenched in good intentions and civic-mindedness that hardly anyone has gone to it expecting actual entertainment. The audiences have sometimes looked as if they were recruited with lassos and nerve gas. As for the plays themselves, perhaps the best thing that could be said of them is that, by and large, they have been easier to sit through than the interminable speeches, award ceremonies and introductions that have surrounded them.

This year, the ACTF tried something new. Using professional (rather than academic) judges, and inviting certain theatrically renowned institutions to bypass the usual screening process, the festival organizers tried to assemble a group of productions that would be worth presenting -- and attending -- on their merits.

As a result, the just-ended 1980 festival, while still in no sense representing the best of a year's worth of college theater (too many colleges declined to participate, and the judging is limited to too small a fraction of every year's output), was a noticeable improvement over 1979. The improvement was symbolized by the selection of Jim Leonard Jr.'s "The Diviners" for the best original play award. "The Diviners," handsomely produced by Indiana's Hanover College, was a crafty, enthralling piece of work and a happy contrast to "The Authentic Life of Billy the Kid," the pretentious ghost play that won last year's award.

Wayne State University's production of "Philadelphia, Here I Come" was another demonstration that the ACTF judges have been playing with a fuller deck this year. Brian Friel's father-son comedy is startlingly similar to Hugh Leonard's "Da" (which happened to be concluding its run at the Eisenhower Theater just when "Philadelphia, Here I Come" came to the Terrace). Both are Irish plays about repressed young men learning to tolerate their fathers -- a silent, stone-faced father in "Philadelphia's" case, and a father full of blarney and blather in "Da's." Like Friel's play, the Wayne State production could hold its own, in many respects, against its Tony award-winning downstairs neighbor.

Certainly Mark Tymchyshyn and Andrew Barnicle, who played the public and private person as of "Philadelphia's" hero, are actors who have nothing to fear from professional competition. If the ACTF helps such talented people establish footholds in the commercial theater, the festival has at least one excellent reason for being.

Pretentiousness, which had been lying mercifully low through most of the 1980 festival, reared its fuzzy head with the last show -- Arizona State University's production of Per Olov Enquist's "The Night of the Tribades," a Swedish play about Swedish playwright August Strindberg, his wife and her lesbian lover, set on rehearsal stage in Copenhagen in 1889. (Tribade is a Greek-derived word for lesbian, literally meaning "she who rubs.") Arizona State's production sought to substitute overwrought acting, bizarre lighting and mysterious props and scenery (including inexplicable statues, crates and curtains done up like ship's rigging) for the basic ingredients the play lacked -- above all, characters anyone could care about.

"Night of the Tribades" reaffirmed what Tennessee Williams proved earlier this year with "Clothes for a Summer Hotel": that merely giving a stage character a famous name doesn't make him important or real. But for all its excesses, this was at least a mildly diverting piece of kitsch, an intriguing in-joke for Scandinavian theater buffs. (And who could resist laughing at this line of Enquist's Strindberg: "The only way for this play to succeed in Copenhagen is to play it in Finnish and to say it's by Ibsen.")

Perhaps the ACTF's most daring and ill-advised innovation for 1980 was to invite a professional theater group, the Dallas Theatre Centre, to stage a play in collaboration with Texas' Trinity University. Ever since the success of Preston Jones' "Texas Trilogy," it appears that Jones' less-talented Texas neighbors have been sizing up Washington as a soft touch for any gossipy down-home comedy from that part of the world. That, at any rate, is the most charitable explanation for how "Ladybug, Ladybug, Fly Away Home," an insufferable sitcom set in the lovely Lady Beauty Parlor of Polly, Tex., could have come into being. Mama Alice and Tish and Margie Lynn and "Ladybug's" other characters are the kind of folks who worship Mike Douglas and Marcus Welby, who dye their hair silver-blue, who wear rainbow-striped pants and who speak in obnoxiously cute local slang sprinkled with obscenities (e.g. "He doesn't know s--- from peach butter").

In her second act, playwright Mary Rohde makes a feeble effort to involve her idiotic characters in a serious morality tale about a home-town girl who has turned to prostitution in San Antonio, but seriousness is just as forced, as predictable and as opportunistic as the comedy that has preceded it. Rohde shows no sign of respecting her own characters, and it is the height of presumptuousness for her to expect anyone else to.

"Ladybug's" opening-night audience included a group of subteen-agers who laughed hysterically at every obscenity -- until their sponsors took them away at intermission. The rest of us -- the so-called adults in the house -- could only wish that we, too, had guardians who would protect us from such rubbish.