It's very old news that theater derives from traditions of storytelling. More recent news, but still old enough, is that the insights in the theater often bubble out from what's unspoken — body language, situations that characters land in, even a stone-faced response by one character to another.

You'd think that after thousands of years of people putting on plays and musicals and puppet shows, there might be a keener understanding of what needs to be said and what doesn't; what allows a theater audience to discover a play's mystery, and the kind of explanation from a character, usually but not always talking directly to an audience, that squelches such discovery. Yet finding those balances is a challenge for writers and directors that lives on.

It would be convenient to blame on TV the presumption that audiences are incapable of discovering for themselves what's going on in a plot, but that would be nonsense. Before heading out to the theater on Sunday, I caught a rerun of ITV's Foyle's War on PBS, transfixed by actor Michael Kitchen, playing a British police detective in the 1940s, and his capacity to listen to a heart-wrenching confession by a murderess while revealing a freight load of skepticism with the mere twitch of an eyebrow, and less.

Curiously, a pair of plays seen over the weekend have abundant merits and yet, varyingly, they love to tell and tell and tell.

Peter Lefcourt has a distinguished reputation in television, receiving an Emmy as writer-producer of Cagney and Lacey. He's also written for Desperate Housewives, among a long list of shows, and has had his plays staged locally, including the comedy Only the Dead Know Burbank at the Hudson Mainstage in 2004, about William Faulkner in a kind of film-studio purgatory.

Lefcourt's latest comedy, Mutually Assured Destruction, just opened at the Odyssey Theatre. The play opens with the amiable Kip Gilman playing Arnie, an L.A. graphic designer who bears a vague resemblance, and has similar vocal cadences, to the young Alan Alda.

Celine Diano's set allows for furniture pieces to roll in and out on casters (the actors do these honors) and for a stylization, under Terri Hanauer's direction, for drinks to be served and drunk from empty plastic goblets. A crude map suspended along the back wall contains black dots on places that will figure in Arnie's central idea, the link between interpersonal and international relations. One character, for example, has her portrait hung on Canada, representing the harmless observer and hapless victim. Another character's portrait hangs over North Korea, representing the potential violence of the aggrieved.

“I miss the Cold War,” Arnie tells us, with a warm nostalgia for when our enemies were clearer than now. At least we could find them on the map, and the lunacy of nuclear proliferation under the policy of mutually assured destruction kept the world safe, or at least safer than it is now.

From this template, Lefcourt unfolds what is essentially a Jewish sex farce, which starts rolling when Arnie discovers his best friend's wife, Eve (naturally), at a clandestine romantic encounter with his accountant, Murray (Bobby Costanzo), at a Mexican restaurant in Canoga Park. This is because, the joke goes, who would discover them in Canoga Park?

Well, Arnie. This is because, being a notorious cheapskate, he drove miles from West L.A. to save $20 on an oil change and wound up in the eatery to grab a taco.

Arnie sees the infidels and flees. But Eve (Brynn Thayer) notices Arnie, and both observer and observed plunge into a guilt-ridden frenzy of threat and counter-threat, bluff and counter-bluff.

Both of the infidels are themselves married. Eve is attached to a stocky stockbroker named Herb, who already suspects that Eve is less than happy at home. As Herb, Stuart Pankin's careening emotions, from blustering rage to howls of forlorn weeping, tap the most ancient traditions of comic buffoonery. Costanzo's Murray is both a lovely performance and a brilliant stroke of casting — the emblem of a tubby bald Jewish accountant doubling as a sex god, even to his gorgeous wife, Myrna (a similarly ribald and comically connected performance by Gwendolyn Druyor).

We see Murray and Myrna have their own sex games, which seem to be working fine. So why is shlubby Murray — an expert in tantric sex — stepping out on her? Some guys are just insatiable? OK.

The central conceit turns on Arnie confessing to an affair he never had — as though his wise wife, Carol (Gina Hecht), would weather that saga.

It's a mix of Borscht Belt stand-up via Roman comedy and its attendant cartoons, and French farce. There are some nice jokes attached to the former — references to an irritable bowel syndrome fundraiser and to the shortcomings of Time Warner.

There also are some uncomfortable ones, as when a white guy (Caldwell in a series of belligerent renditions) impersonates a Korean waiter who pretends not to understand English. The joke is aimed at Eve's imperiousness, but with the waiter played by a guy belonging to the ethnicity that calls the shots, it's on the line between witty and demeaning. A similar moment is when a Vietnamese beauty clinician (Caldwell again) recites atrocities from the war in Vietnam while sadistically administering a Brazilian wax job to her American clients.

More to the point, with Arnie and his tawdry cohorts explaining via audience address what they're thinking and what they plan to do next, the ricochet effect of French farce starts to implode.

If a play is going to traffic in cartoons, as this one does, they really need to keep bouncing off the walls — so fast that we miss the various improbabilities. Breaking the fourth wall allows for a kind of winking humor. Yet those same intrusive reflections by various narrators allow us time to consider the play's shortcomings.

Playwright-performer Jay Jacobson creates a trio of characters in his very reflective solo show, Mental Creatures, at the Lounge in Hollywood, directed by Randy Brenner. Imagine John Leguizamo in slow motion, ruminating on the purpose of artistic ambition, on success, on opportunities that slipped away, on aging. Jacobson is a gentle bear of an actor, impersonating a painter who's now rolling into his 30s, still struggling to land a show in a gallery. He's feeling life and its possibilities slipping away.

He also portrays a former Jewish ballerina, now 59, who holds the memory of one performance at Lincoln Center as the crux of her identity. She gave it up for a husband who died prematurely, so now she lives alone in a condo, pressured by a friend to date. Scenes of her blind dates, in which Jacobson portrays all parties, are among the highlights of this tender show.

Finally, there's a retiree, a widower, cradling memories of his late wife and his late life, leaving his home, dispensing of mementos and relics in order to live in a care facility and be visited by his son maybe once a week.

Throughout, Jacobson sweetly sings his own songs to recorded accompaniment. The titles give you a sense of the show's tone: “Human Nature,” “This Is Life.”

The beautifully rendered characters give away too much, overstating the obvious so that pathos slips a notch into lugubriousness.

Yet a line such as “Neurosis is a substitute for real suffering” brings home the realization that Jacobson knows a thing or two, and that the sadness blanketing his performance is born of integrity.

MUTUALLY ASSURED DESTRUCTION | By Peter Lefcourt | Presented by Theatre Planners at the Odyssey Theatre, 2055 S. Sepulveda Blvd., W.L.A. | Sat., 8 p.m.; Sun., 3 p.m.; through Aug. 26. | (323) 960-5772 | plays411.com

MENTAL CREATURES | Written and performed by Jay Jacobson | Lounge Theatre, 6201 Santa Monica Blvd., Hlywd. | Thurs.-Sat., 8 p.m.; through Aug. 18 | (323) 960-7738 | plays411.com

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