God of Carnage regresses from social restraint to four blithering adults struck by Tourette’s.

Before God of Carnage begins at the Old Globe’s White Theatre, Robert Morgan’s set makes a quiet suggestion. Dark objects stand on the perimeter of a circular living room. A small wet bar and sofa are dimly lit on the raised floor. Beyond them, darkness. In the center, under a shimmering cone of light, pink tulips in a glass bowl flare outward. The scene is unfussy, the details few, and the flowers really stand out from the drab surroundings — so much, in fact, that if you squint just a tad, the living room comes to resemble a solar system: the sunburst of tulips radiating into empty space.

Morgan doesn’t press the point: he hasn’t arranged the furnishings like planets, or some such. But maybe playwright Yasmina Reza does. The title and what happens to the precise, sun-centered set imply that humankind may not have come a long way after all, baby.

Or, to reverse Hamlet, there is less to Heaven and Earth than is dreamt of in our philosophy.

The cause: at 5:30 p.m., November 3, 11-year-old Benjamin Raleigh struck young Henry Novak in the face with a stick, resulting in a swelled upper lip, two broken incisors, and possibly an injured tooth nerve. The event/assault took place at Cobble Hill Park, which the Novaks were convinced was a “haven of safety.”

The strategy: The Novaks — okay, Henry’s mother Veronica — demand a pow-wow with Benjamin’s parents. The Novaks want...what? Accountability? A written statement of guilt? It’s clear (at first, at least) that Michael Novak, who sells household goods, and wife Veronica, a writer, want young Benjamin not only to understand what he’s done, but to repent.

Later, Veronica will explain: “We’re living in America according to the principles of Western society. What goes on in Cobble Hill Park reflects the values of Western society!”

The Novaks wear casual attire. It’s their universe — er, home. Annette Raleigh, who works in “wealth management,” and Alan, a lawyer with corporate clients, sport basic black suits. These two are tailored. Their time is money.

Veronica frames the encounter by saying, “Fortunately, there is still such a thing as the art of coexistence.”

The effect: The center does not hold. In inevitable, hilarious stages, God of Carnage regresses from social restraint to four blithering adults either struck by Tourette’s syndrome or what Bob Dylan calls a “truth attack.” Things, even the tulips, fall apart.

Yasmina Reza has always cast a cold eye on civilization. In her translation of Kafka’s Metamorphosis (for Roman Polanski), Gregor Samsa isn’t the only bug in town; her Art — about over-the-top reactions to a blank canvas — has toured theaters around the world. She’s also fascinated by what lies beneath the surface. In The Unexpected Man, she paints a brilliant portrait of the turmoil in a famous writer’s mind (it may not have enough appeal for a full staging, but I wish a local company would do a reading: it’s the best account I’ve ever read on the subject).

In Carnage, the surface itself is strange. How many parents call meetings like this? And why does it begin as formally as an affair of state? The parents even quibble about the wording of an indictment. Embedded into the surface, however, is a cross-section of attitudes and values, from progressive, both token and earnest, to conservative, to — as Michael Novak unpeels his sweater and his gregarious veneer — Cro-Magnon.

After awhile, as if playing “Survivor: The Home Game,” the sides shift, then break down, then recombine. Each new twist becomes more Darwinian. (Reza plays an ongoing game with the audience: can I top this? In the next scene, she does.) You may find yourself becoming defensive: they’re just four people trapped in a farcical vortex, surely they don’t represent us.

Reza writes plays for actors. In Carnage, the characters don’t have traditional arcs, moving from A to B; they’re more like precipitous falls from grace. Under Richard Seer’s expert direction, all four actors get a workout at the White Theatre.

At first, Caitlin Muelder’s Annette is so repressed, she’s almost bolted down. Veronica reads her correctly: Annette just wants to smooth things over and move on, neither healing nor growing from the experience. By play’s end, owing to fierce encounters and ten-year-old rum, Annette leaves the stage a liberated being.

“A mouthful of rum and — bam — the real face appears,” the playwright has Michael say (tipping her hand in the process).

The show has no intermission. If it did, you’d swear a different actor played the later Annette — business suit a frump, hair spiking, eyes ablaze — the two are so far apart. Same with the others. Erika Rolfsrud’s Veronica shifts from a committed (and controlling) problem-solver to a loose cannon. Lucas Caleb Rooney’s hamster-hating Michael salutes the “god of carnage” and devolves before our eyes. T. Ryder Smith completes the quartet — “A Fugue for Omnivores”? — as Alan. He begins as someone who doesn’t belong, doesn’t have time for prosaic problems.

And here’s where the playwright ups the ante. Michael’s biggest client, a pharmaceutical firm, is in trouble — deep, seven- or even eight-figure lawsuit trouble. We learn this because he spends much of his time on a cell phone trying to mollify the maniac on the other end. Each call escalates, as does Alan’s breakdown.

The cell phone’s a fifth character. As in TV commercials or time-outs at sporting events, it connects and disconnects at the same time: it brings in the outside world but interrupts the flow of life.

If you don’t want to generalize, Carnage is just a goofy farce with low-comedy shtick (including the most believable stage-vomiting seen in these parts). But, starting with the set and adding Reza’s many cues (as when Alan asks, “are we ever interested in anything but ourselves?”) and the pharmaceutical scam that may include millions, it becomes more and more difficult to contain this comedy of manners to the stage. It insists on including those seated in the darkness. ■

God of Carnage, by Yasmina Reza

Old Globe Theatre, 1363 Old Globe Way, Balboa Park

Directed by Richard Seer; cast: Erika Rolfsrud, T. Ryder Smith, Lucas Caleb Rooney, Caitlin Muelder; scenic and costume design, Robert Morgan; lighting, Chris Rynne; sound, Paul Peterson

Playing through September 2; Sunday, Tuesday, and Wednesday at 7:00 p.m., Thursday through Saturday at 8:00 p.m. Matinee Saturday and Sunday at 2:00 p.m. 619-234-5623