When one of the besieged security guards in “The End of Reality” laments that “we get older, whether we grow up or not,” it’s hard not to suspect that playwright Richard Maxwell – who has insisted in the past that he’ll break from his trademarks if he senses they’ve become formulaic – shares this concern.

Mr. Maxwell, whose flat-affect domestic dramas have turned him into our generation’s most provocative anti-dramatist, has begun tiptoeing his way toward what passes for real life in his numbed theatrical universe. But his footing on this new path is far less secure.

Mr. Maxwell’s defiantly banal texts and static productions, which often rely heavily on non-actors, have shown an astonishing ability to subvert any conventional notions of narrative drama. And “The End of Reality” promises an equally refreshing milieu, a sort of existentialist “Assault on Precinct 13.” But he has spiked his new play with increased physicality and a jarringly unsuccessful nod to naturalism.

The play opens with a collegial batch of guards hanging around in a building lobby and nattering on about working out, an upcoming movie audition, filling out paperwork, and so forth. Rarely do they peek at the security-camera feeds visible on an upstage projection screen, but they don’t appear to be missing much.A few balloons hang in a lobby, the occasional employee drifts past, the desk chairs don’t look very comfortable. (Nor do the utilitarian chairs and tables that make up Eric Dyer’s spartan set.)

The front desk seems drastically overstaffed, in fact, until a lanky fellow in a wool cap (an imposing Jim Fletcher) saunters in and kicks up a ruckus. Clad in elbow and knee pads, he walks in, grabs a guard, and violently drags him off the stage. The fight choreography that unfolds looks tentative, almost klutzy. “It happened so fast,” one of the remaining guards gasps in the aftermath, and yet the abduction unfolds with comically deliberate speed.

This disjunct between what is said and what is experienced, a central part of Mr. Maxwell’s oeuvre, is used to sharp effect early on: Fiery laments to the departed guard are performed with the same cadences and passion as mindless chitchat about a new cigarette brand. But then the actors and non-actors begin … acting. Starting with a line here and there, the flattened delivery repeatedly gives way to a more naturalistic, “normal” style. This may become a vital tool in Mr. Maxwell’s arsenal – someday. For now, though, it results in an unappealing sort of performative limbo: With the exception of Thomas Bradshaw, the actors are too stilted to be natural and too natural to be transporting. What had served before as an uncanny channeling of his plays’ numbing milieu now just seems like bad acting.

Also gone are Mr. Maxwell’s sludgy pop tunes, which have traditionally been sung with a bare minimum of conviction and vocal prowess. (The pianist was invariably forced to plink out the melody with one finger if the singer was to have any chance of getting through it.) Instead, the emotional release is provided through a series of increasingly intricate – and distancing – fight sequences staged by Brian Mendes, who also plays the alpha male among the guards.

After one such battle, the weary guard Tom (Mr. Bradshaw, the actor who adheres closest to Mr. Maxwell’s usual cadences) admits to a “refined arrogance,” and the phrase also jumps to mind concerning Mr. Maxwell. Did he sense this trait in his own continued reliance on specific theatrical devices, prompting him to switch gears, albeit cautiously? His last play,”Good Samaritans,” featured a somewhat traditional love story between two wounded souls, but the tale was told with his trademark opacity. While a similar romance blooms here between two guards, Mr. Maxwell indulges this burgeoning relationship far beyond the breaking point.

A huge chunk of “The End of Reality” is devoted to a soul-baring monologue by Marcia (Marcia Hidalgo), the female half of this romance, who has temporarily apprehended and handcuffed the intruder. The speech covers martyrdom, sibling rivalry, and school dances, plus several other things, and long before she finishes, one’s eyes shift wearily to the interloper lying on the ground in front of her. He has been watching, stretching, and occasionally making half-hearted attempts at freeing himself, but he finally rolls onto his side for a little shut-eye. The response is understandable.

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Madelyn Kent originally wrote “Peninsula” in Spanish, a language in which she is comfortable but hardly fluent, and the translation to English for the current production at the Kitchen has only exacerbated the hiccups, gaffes, and redundancies that plague the entire production.

“Peninsula” is an ultimately fatiguing mix of Mac Wellman’s self-negating wordplay and Vaclav Havel’s spooky/loony political ambiguity. The eponymous locale seems deliberately opaque: venturing off it is discouraged and explosions are routinely heard in the distance. And though civility may be valued, folks can also disappear mysteriously.

People have very different ways of coping in this ominous world. Flora (Marielle Heller) spends her afternoons stealing from and/or seducing a series of shopkeepers, telling her unnamed husband (David Chandler) that she’s visiting an old lady, while he wrestles with his guilt over leaving a murkily defined “group,” and a priest (Tim Cummings) abandons his dogma to become a corporate raider.

But while the actions of these uncertain souls may vary, their language is remarkably similar. It’s unclear exactly what deprivations have been visited upon this land, but English teachers appear to have been an early casualty. Its inhabitants sometimes sound like Latka on “Taxi” (“Says the truth I disappoint a little”) and sometimes creep unnervingly close to stereotypical Negro dialect (“Who be your friend?”). Once in a while they correct themselves, or others do it for them, but usually the flubs remain unchallenged. Language is as splintered in this fascist state as the other forms of interaction.

The most telling lapse in syntax is an evasion of, or perhaps an aversion to, verb tense, as when Flora says to a beggar,”Forgave me,” or her husband asks her, “Did you meet the old lady nowadays?” As rattling as the question “Where am I?” can be, it pales here in comparison to “When am I?” Ms. Kent offers one reason for this temporal confusion when the husband confesses,”It is no good remember. Remember only leads to problems.”

Ms. Kent has directed her own work here, which may not have been such a good idea. Hermetic, cryptic worlds can be hard to convey to an audience. Sometimes this is best done by the person responsible for that world – the author – and sometimes it benefits from the mediating influence of an outsider. The latter holds true here: A sameness begins to settle over the material, and Ms. Kent fails to guide the actors toward a performance style that would make sufficient sense of this foreboding land and its tortured, splintered syntax. (The one exception is Mr. Chandler, who gives his character a beleaguered, raspy weight.)

Ms. Kent has marshaled an impressive physical production, though. Matt Frey’s deceptively simple lighting design casts a painterly series of nourish half-shadows over the haunted characters, and Narelle Sisson’s almost two-dimensional set – a series of diorama-like interiors arrayed across the stage – makes ingenious use of Soho Rep’s wide seating configuration.

But Ms. Sisson’s set isn’t the only flat thing on display. As intriguing as Ms. Kent’s pervasive linguistic quirks are at first, she never provides the narrative spine or the political urgency that might support them. “There’s too much of the world,” Flora complains to one of her conquests, but from an outsider’s perspective, there isn’t enough of it. In its absence, this potentially illuminating examination of language in the face of oppression becomes an extended parlor trick. Says the truth I disappoint a little.

“The End of Reality” until February 4 (46 Walker Street, between Church Street and Broadway, 212-868-4444).

“Peninsula” until January 28 (512 W. 19th Street, between Tenth and Eleventh Avenues, 212-555-5793).