THE REPETITION of "heads or tails" in the opening scene of Tom Stoppard's Rosencratz and Guildenstern Are Dead seems ironic, because the play is now worn like an old coin from passing through the hands of so many directors. Although it's been 16 years since its original minting, this weekend's Dunster House performance of Rosencrantz and Guildenstern hasn't lost its edge. The innovation of two Shakespearean anti-heroes on center stage, the stark contrast between Elizabethan and modern language--and the themes of the finality of death, the role of fate and the insignificance of human life--are not dulled even after many staging. Director Roger Kaplan's interpretation, while not radically different from others,' lands "heads up" with a lively presentation.

The stage is spare--swathed in a smoothing blue gauze--forcing the actors' charisma to sustain the show. Rosencrantz (Jim Torres) and Guildenstern (Steve Kelner) meet this demand; with exaggerated facial expressions and wild gestures, their compressed energy matches Stoppard's verbal swashbuckling, his inevitable bons mots.

As roles, Rosencrantz and Guildenstern present a unique difficulty--while at times interchangeable, the characters must create enough tension to sustain interest. The actors handle this problem well: Both bearded and flashing sparkling eyes, they at once mesh with and foil each other. Kelner's quizzical manner provides the needed contrast to Torres' air of blank amusement.

Only the players seen through the blue gauze remind the audience of the play's links with Hamlet and with tragedy--when the down-at-the-heel band of players doubles as Denmark's familiar royal family. The troup's leader (Kevin Jennings) confronts the bewildered Rosencrantz and Guildenstern with a one-upmanship that never flags. As both the king and the head Player. Jennings plays with vigor and consistency the role of crafty manipulator, impressing upon the audience Rosencrantz and Guildenstern's powerlessness to control their fate.

Indeed, they are helpless before more than the Player's guile--and know it. During the second act of the play the two speculate on the nature of death, comparing it to being inside a lidded box: "Life in a box is better than no life at all. . . You'd have a chance at least. You could lie there thinking--well, at least I'm not dead! In a minute someone's going to bang on the lid and tell me to come out," Rosencrantz says.

On another level, being encased in a box symbolizes not only death's inescapability but also the characters' limitations within the constraints of the original Hamlet. Stoppard wanted to emphasize these limitations by confining Rosencrantz and Guildenstern to their original roles as bit parts, servants of greater wills. He magnifies the characters without strengthening them--even in their own play they remain ineffectual word-wielders with no more identify than they had as Shakespeare's tools.

IMAGES OF ENTRAPMENT recur: Boxes appear on stage, both as tables and as a way for the players to appear and disappear. The effective use of curtaining to exclude Rosencrantz and Guildenstern from the rest of the players, and the thorough if unimaginative use of lighting to blacken the set completely, emphasize the duo's--and the audience's--helplessness. Like the players in Hamlet, we feel as if we are on the fringe of the real play that is slightly out of our sight. At times we are plunged into total darkness and feel the same apprehensions as Rosencrantz and Guildenstern.

Another trap in Stoppard's play is the confining of rich, mock-Elizabethan dialogue to a spare, absurdist setting--as critics have pointed out, Rosencrantz and Guildenstern draws heavily from Samuel Beckett's style. But director Kaplan perhaps tips the scales too heavily toward the absurd tradition. The stark stage, the sparse furniture are all there, and rightly so. But the Shakespearean tradition is just as important: Stoppard includes sizable chunks from Hamlet, and his own words show a penchant for language tricks:

"It really boils down to symptoms. Pregnant replies, mystic allusions, mistaken identities, arguing his father is his mother, that sort of thing. . . Knock-kneed, droop-stockinged and sighing like a love-sick schoolboy, which at his age is coming on a bit strong."

By slowing down the fast-paced delivery. Kaplan might have reinforced the contrast inherent in Stoppard's play and done more justice to the Hamlet half. For the near-antithesis between the two voices, the Shakespearean prose and the Beckett-like, riddling repetitions, lead to the play's core: Hamlet's tragedy as seen from side-stage, through the Godot-like absurdity of two characters who are not the least bit heroic.