In the often-thrifty world of local theater, this fascinating show is one of the few I've seen that might benefit from even more minimal staging. Tarell Alvin McCraney's play (running through Sun., Dec. 21) is rich in emotion, but theatrically it's spartan by design: McCraney says he wrote it to be played on a sidewalk, and you can see how it would work. Three actors portray two African-American brothers in rural Lousiana and the just-paroled younger brother's mysterious prison buddy. That the actors speak many of their stage directions aloud (in formal voices distinct from those of their characters) gives the play a ritual, almost mythic quality -- McCraney was inspired by Yoruba culture -- and makes props unnecessary, if not superfluous.

Brothers Size is about many things, including longing, loneliness and the paradoxes of being one's brother's keeper. Often, like the plays of August Wilson (to whom rising young artist McCraney not long ago served as assistant), it's about the pleasures and tensions of men hanging out together -- of talk, even. But it's distinguished from Wilson by (among many things) the small size of its cast and its stylization: Fences without a back-porch set, and Two Trains Running absent Memphis Lee's Hill District diner counter, would lose more than Brothers Size would sacrifice without the incarnation of older sibling Ogun's auto shop we see here, with its battered garage doors and ancient Esso sign.

While the well-designed Brothers set, in City's intimate Lester Hamburg black box, is appropriately gritty, the production is relatively lush: There's a fairly elaborate sound design, for instance, and special lighting effects. I wondered whether director Robert O'Hara could add by subtracting. Ogun already mimes digging with a shovel, so why does he need to lock a real box wrench onto a real metal frame (doubling as a chassis)? The spoken stage directions tell us dream sequences are coming, so what would be lost without the floor lighting and echo effects on the voices?

These are quibbles, of course. With an outstanding cast of Albert Jones, Jared McNeil and Joshua Elijah Reese (the latter one of Pittsburgh's best young actors), O'Hara has staged a wrenching show. But I couldn't help remembering how (in an interview in the weeks before opening night) McCraney harked to that chestnut about theater as shared illusion, and how the more you make audience members imagine, the more your accomplices they become.