DEATHTRAP - At the Eisenhower Theater through September 1.

There is remarkably little material in "Deathtrap," the Ira Levin murder play at the Kennedy Center's Eisenhower Theater. One Eeeeeek!, one that has sustained the play for two years in New York and London, where a lot of people relish the Eeeeeek!s. It's not gimmicky, but effective, at least the first time. The second time, some of the thrill is gone.

But the plot idea is even skimpier, if one can call an idea the oldest solution to writer's block, which is to write about the nearest thing at hand, which is always the problem of a writer who has writer's block. No thrills and surprises there - the minute the raised curtain reveals a desk, a typewriter, and an attractively graying man in a comfortable sweater, we all know what's coming.

The second minute after the curtain goes up on this one, that character tells us he is a playwright reading a play called "Deathtrap," and suggests the idea of a graying, etc., playwright murdering a fresh young playwright to take away his play idea. That one spurt of inventiveness is it for the play we are seeing. This idea is then acted out, read aloud as a play within the play, explained as a fear the playwright's wife has, recited by a neighboring psychic as a prediction, recounted by her again to show that the prediction came true, marveled over by the family lawyer, and so on.

The rules are also repeated: The play must have two acts, three scenes each, with five characters, as indeed, "Deathtrap" does. One can sell related T-shirts are for sale in the Grand Foyer. One needs a comic character for relief, it's stated, and who should show up but a hefty lady with a funny accent who sees a vision of a typwriter and thinks it's a black man called Smith Colonna.

Each of the five characters says that the idea is bound to make a commercial hit play. The writer-hero, played by Brian Bedford in what seems to be a state of bemused perplexity, tells us that "Deathtrap" is a marvellous title. He follows his mildly amusing lines with the notation, "Hey, that's a good one - maybe I can ease it in somewhere." And we are told that "Act II is liable to be a letdown," which is true, too.

Audience reaction is anticipated in the play, as well. When they aren't marveling over the plot, the characters suggest that one might consider it "contrived theatrics" with "glib, superficial characters." It's not that bad, but Levin forgot to tell us from the stage exactly how much we should reassure him. CAPTION: Picture, BRIAN BEDFORD SHOWS KEVIN CONROY A PAIR OF HANDCUFFS ONCE OWNED BY HOUDINI IN "DEATHTRAP."