"Cockfight Play," Directed by James Macdonald, at the Duke "Cockfight Play" is not the title of the terrific, tense little comedy by Mike Bartlett that opened on Thursday night at the Duke on 42nd Street. Its real name, which is only one syllable, is unprintable here, and "Cockfight Play" is being used in advertisements in family newspapers. Yet there is occasionally truth in even the subterfuges of advertising. And as it happens, the publicized title is an accurate description for the experience of this feisty, hypnotic and oddly energizing exercise in emotional carnage, which has been directed (by James Macdonald) and acted (by a four-member ensemble) with a brute focus that suggests to-the-death battles of penned animals. Come to think of it, although the subject of ancient Rome comes up only once, in a fleeting conversational reference, "Gladiators" wouldn't be a bad name for this production either. As redesigned for the occasion by Miriam Buether, the theater at the Duke brings to mind a scaled-down Roman coliseum, with tiers of seats rising in a circle around a central clearing. There is no scenery, no props - just four combatants having at one another in ways both visceral and ritualized. Jason Butler Harner, the first actor to appear, wisely takes off his watch and hands it to a woman on the sidelines before he enters the play, or fray. It's a symbolic stripping down for action in a contest that, for the record, features no visible nudity, although at least three of the performers here get about as naked as they can in all but the literal sense. This impression of acting in the raw befits a work about sexuality, selfhood and the intersection of the two. First staged at the tiny upstairs space at the Royal Court Theater in London in 2009, "Cockfight Play" instantly made the reputation of Mr. Bartlett, then still in his 20s, as a writer who had reinvented the wheel. Or, to be precise, the triangle, that multipurpose dramatic configuration that has been in use since the days of Aeschylus. The setup is diagrammatically simple, a quality that Mr. Bartlett has underscored by identifying three of his characters only by single letters. The fourth is John (Cory Michael Smith, in a breakout performance), a young man classically torn between two lovers. One of them is M (Mr. Harner), with whom John has been living for some time. The other is W (Amanda Quaid), with whom John, to his gratified surprise, goes to bed soon after they meet. Yes, that's M for Man and W for Woman. The identity of John, who feels the erotic and emotional tug of both, lies somewhere between these starkly signified poles. If the truth be known, he would rather not have to make up his mind. But what's a lad to do when those laying claim to his, uh, hand are pulling him so hard in opposite directions that he threatens to split in twain? There hasn't been much novelty in gender-straddling stories of sexual choice since the 1970s, when films ("Sunday Bloody Sunday") and Broadway dramas ("Find Your Way Home") brought the subject to mainstream audiences. It's not Mr. Bartlett's topic that makes his play feel daring, or even the implicit debate he opens about what we're physically attracted to, and why. What gives this work its punch and its invigorating lifeblood is something more primal, though it's rendered in utterly contemporary terms. That's Mr. Bartlett's keen and dispassionate evocation of the will to control, to consume, to possess, which that thing we call love often brings out in us, especially when it seems threatened. Mr. Smith's John - who is a spindly guy with few of the usual attributes of Adonis-like hommes fatals - is so very attractive in large part because he has so little will of his own. "Some people might think you were scrawny," W says to him, "but I think you're like a picture drawn with a pencil. I like it. You haven't been colored in. We're so often told that confidence is an aphrodisiac that we forget that the absolute lack of certainty can cast a similar spell. Asked just what makes him so appealing, John answers, straight-faced, "My eyes." You know what he means. There's unsolidified, energy-packed potential in that gaze. And you can see why M and W, who deftly use very different forms of emotional blackmail, want John as someone whose very fate they can determine. That, after all, is true power. It is as a power play, if you will, that this production succeeds so beautifully. Written in short, elliptical scenes, divided only by the sound of a bell, "Cockfight Play" has been staged with a stark and limpid formality that only underscores the churning, messy feelings beneath. The characters rarely touch, though as they speak it's evident that they're often doing quite a bit more than just touching. And I can't remember the last time that sex onstage felt so authentic. Mr. Macdonald has an excellent track record in making maximal use of minimalism (Caryl Churchill's "Drunk Enough to Say I Love You?" and "A Number," Christopher Shinn's "Dying City"), but he doesn't repeat himself here. To portray a triangle, he works in circles. The characters (there are often only two onstage at a time) walk around each other slowly and assessingly, like fighters sussing out an opponent's strengths and weaknesses. Sometimes they move toe to toe, swaying gently, in a mutually mesmerizing rhythm. The dialogue is naturalistic, often very funny and often fragmented, as if complete sentences couldn't contain the welter of appetites and intentions within. The cast members - who also include Cotter Smith as M's father, F - are superb (assumed British accents and all), and they find the particular charm and rhythm of their characters. We understand what connects them and sets them against one another. The last 15 minutes of this uninterrupted 90-minute work, in which all the characters gather for a hellish dinner party, are its most conventional and, for me, least satisfying. Mr. Bartlett articulates the terms of his debate quite baldly here, in almost Shavian terms, which diffuses the tension of the more oblique preceding scenes. Or it would, if the performers didn't hold on to the scene's every moment as if it were a lifeline. In a way, it is. The play's final image, which finds a single figure crouched center stage, evokes classical sculptures of a gladiator in his death throes. This is how such competitions end. But there is definitely doubt as to whether anyone has wound up a victor. Cockfight Play By Mike Bartlett; directed by James Macdonald; sets and costumes by Miriam Buether; lighting by Peter Mumford; sound by Darron L West; production stage manager, Martha Donaldson; production manager, Aurora Productions; general manager, Davenport Theatrical Enterprises; associate producers, Kevin Emrick and Patrick Daly. Presented by Stuart Thompson, Jean Doumanian, Royal Court Theater, William Berlind, Scott Delman, Dena Hammerstein, Jon B. Platt, Scott Rudin, Ted Snowdon and True Love Productions. At the Duke on 42nd Street, 229 West 42nd Street, Manhattan; (646) 223-3010, dukeon42.org. Through July 22. WITH: Jason Butler Harner (M), Amanda Quaid (W), Cory Michael Smith (John) and Cotter Smith (F).