From the Pulitzer Prize-winning playwright David Lindsay-Abaire comes the production of “Good People,” a social drama and dark comedy that takes place in South Boston’s Lower End. Starring Johanna Day and Andrew Long and directed by Jackie Maxwell, “Good People” runs through March 10 at Arena Stage. (The Washington Post)

The people of “Good People” aren’t all that good — which is partly why the play is better than good. As consequences of David Lindsay-Abaire’s wisdom-filled script and Jackie Maxwell’s superbly modulated direction, the evening in Arena Stage’s Kreeger Theater delivers robust helpings of insight and laughs.

It’s a caliber of production that reminds you how nourishing theater can be, how a play can supply edifying commentary on our turbulent times without forgetting its goals as entertainment. You will find in “Good People” plenty to put you in a pleasant frame of mind, even as it attempts to document some disquieting truths about American class envy and contempt, and some limits of the impulses to compassion and generosity.

No wonder, in an age when more and more, charity seems to end at home, it is the most oft-produced play on the nation’s stages this season.

The superior standard is set at the top of the cast, and filters down to the smallest (and still quite significant) of the six roles. In the crisp tale of an out-of-work single mom from hardscrabble South Boston, who reaches out to an ex-boyfriend-turned-wealthy-doctor, the workhorse role is that of blue-collar Margie Walsh. As played with endearing gumption by the smashing Johanna Day, Margie is a straight shooter who is so Southie-proud — even the “g” in her name is hard — she wears her financial struggles like a crown.

She’s just been fired from her $9-an-hour cashier’s job at a dollar store; she’s late on the rent to her tolerant if unpredictable landlady, the aptly named Dottie (Rosemary Knower), and worn out from caring for the unseen Joyce, her grown-up, mentally disabled daughter. If that is not a recipe for audience sympathy, what is?

(L to R) Johanna Day as Margie, Francesca Choy-Kee as Kate and Andrew Long as Mike in Arena Stage at the Mead Center for American Theater’s production of Good People. (Margot Schulman/Margot Schulman)

Well, not so fast. Or at least, not so simple. How can it be that everyone in “Good People,” even Margie, clearly recognizes the unhelpful or hurtful inclinations of others, but can’t see it in themselves? “You have to be a selfish [expletive] to get anywhere,” one of the characters, who hasn’t gotten anywhere, opines. The notion of selfishness — the extremes we go to, looking out for No. 1 — materializes in the play again and again: in the ease, for example, with which Dottie gravitates to the idea of throwing Margie and her daughter out; in the craven encouragements of Margie’s pal Jean (a hilarious Amy McWilliams, as the play’s throaty voice of plain talk); in the tentative yet heartless way that Stevie (Michael Glenn) dismisses Margie from her job.

And most combustibly, in the wonderful culminating scene in Act 2, when Margie sandbags her old flame Mike and his young wife Kate (the outstanding Andrew Long and Francesca Choy-Kee), in their luxurious home in a Boston suburb, where Margie is so out of place that Kate mistakes her for a delivery person. (Kate’s ethnicity is further fuel for the fire.) Put off by Mike’s skittishness at offering her any kind of help, Margie lashes out with a story calculated to drive a wedge between the doctor and his spouse — an act that sparks a passionate rebuke from Choy-Kee’s Kate, expertly spitting the bile back in one of the evening’s best speeches.

Maxwell, artistic director of Ontario’s Shaw Festival, has a surefire ear for comedy: This “Good People” is even funnier than the excellent 2011 version with Frances McDormand at Manhattan Theatre Club. The amusing results are thanks in big part to the convincing mix of abrasiveness and camaraderie conveyed in the kitchen and in Bingo scenes among Day, McWilliams and Knower, and the success of endearingly risible bits, such as Dottie’s habit of gluing hideous Styrofoam balls to ceramics and selling them as curios.

Day, who last appeared at Arena as a New Age-y Californian in 2009’s “The Quality Life” and before that was Lizzie Curry in a revival of “The Rainmaker,” has in Margie a role that seems ideally contoured to her talents. There’s so much conviction in her weary though undefeated countenance that you can’t help but root for her; when she shows up at Mike’s Boston office, offering herself as a janitor, the courage tinged with vulnerability makes her irresistible. To Mike’s declaration that his circumstances are comfortable, Day ensures that Margie’s reply — “I guess I’m uncomfortable” — strikes just the right wistfully ironic note.

Long, portrayer for Washington audiences of Mark Antony and Henry Higgins, nimbly sidesteps the pitfalls here of arrogance or entitlement; you sense the scruffier character existing beneath the more polished surface. And McWilliams, as a waitress forever having Margie’s back, avoids turning Jean into a refugee from a working-class sitcom. She brings Jean’s wise-gal retorts in for admirably soft landings.

If one production element might be integrated a bit more harmoniously, it would be Todd Rosenthal’s realistic sets. The dingy shingles of a Southie back alley are rendered with credible grunge, but the Kreeger stage is overburdened by multiple sliding scenic pieces for offices and homes that must be shlepped on and off; at one point, a Bingo scene occurs in front of Mike and Kate’s upscale manse.

A Bostonian might conclude, too, that a few of the accents belonged to chowdaheads. On the other hand, Linda Cho’s costumes, especially the outfits she chooses for Margie and Kate to illustrate their wide disparity in taste, are — like “Good People” itself — wicked great.

Good People, By David Lindsay-Abaire. Directed by Jackie Maxwell. Sets, Todd Rosenthal; costumes, Linda Cho; lighting, Michael Gilliam; original music and sound, James Sugg; dialects, Anita Maynard-Losh. About 2 hours 20 minutes. Through March 10 at Arena Stage, 1101 Sixth St. SW. Visit or call 202-488-3300.