David Mamet’s territory is the burned-out shell of the soul. His best-known plays and films are peopled with losers clinging to pathetic illusions, spitting out their bitterness in the elliptical, fragmented language that has come to be known as Mametspeak. The chatter running through the 1977 play American Buffalo gives it its life and, in a way, its very meaning. Much of the dialogue is cadenced in decidedly un-Shakespearean iambic pentameter: “The fucker won four hundred bucks last night.”

The current production by Jack Shea’s Actors Company is part of Westfield State College’s summer-long Masters Festival of the Arts. Other events include music concerts and an exhibit of works on paper by major American artists in a gallery adjacent to the theater.

The three men we meet in a Chicago junk shop live on the underbelly of society and at the edge of the law. Easygoing Donny (Frank Aronson) is the shop’s proprietor and a father figure to young Bobby (Josh Raymond), who hangs around the store and runs errands. Teach (Jack Shea) is a testy small-time hustler with lots of mouth and not much hustle.

The plot turns on a nickel—a rare Indian-head, or buffalo, five-cent piece Donny sold yesterday to a passing coin collector for an unexpectedly high price. That windfall inspires a half-baked plan to burglarize the customer’s house and steal his entire collection. These men aren’t criminals, exactly, but ordinary Joes who do a little crime when it comes along—not immoral but, like most of us, fitting their morality to their needs.

Nothing much happens in the play, which runs through an afternoon and rainy night. The aimless, compulsive talk is rooted in the moment. Every other word is an obscenity, every other thought a repetition of the previous one. There’s no reflection, hardly even memory; we learn nothing of the characters’ histories before yesterday.

The play gets its holding power from its brilliantly observed moment-to-moment action—or rather, turbulent inaction. And Jack Shea’s staging (he’s the director and producer as well as performer) slashes the physical production, usually dominated by mountains of junk-shop clutter, to its bare bones.

The playing area in Westfield State’s black-box studio theater is an open square with the audience seated on four sides and a round table dead center, littered with debris from last night’s poker game. Under Panagiota Kanavaros’s moody lighting, the setup evokes a boxing ring where inept fighters hopelessly spar.

The opening-night performance took some time to gather momentum. The first act seemed at once tentative and over-rehearsed, but Act Two crackled with emotional electricity equal to the thunderstorm raging outside the shop. And while still searching for a cohesive ensemble, the three performances are persuasive.

Shea is a jumpy, neurotic Teach, cocky, paranoid and obsessive. Aronson finds just the right balance between Donny’s rough finish and soft heart. And Raymond gives Bobby a puppylike eagerness that’s constantly overwhelmed by drug- and life-induced confusion.

This show will be followed by quite a different Mamet play, the period comedy of sexual jealousy Boston Marriage, this one with a cast of three women.

American Buffalo: Ely Studio Theatre, Campus Center, Westfield State College, through July 10. (413) 572-8835..