Considering that marriage boils down to a legal contract, a whole lot of fuss gets made over the marginalia. Excess concepts like monogamy, love, and all that gush should be reduced to “rider” status; the body of the document should have a much more straightforward focus. After all, they call them the “bonds of marriage” for a reason, and as such they appreciate slowly (only increasing in value when they aren’t cashed in).

That, at least, is W. Somerset Maugham’s rather refreshing view of the hoary institution: Marriage works as an economic arrangement, best approached with a cool head and a reassuring pat to the checkbook. Stuff conventional fidelity, his heroes cry, and leave the small-minded to pick up the pieces.

The Roundabout, lightening up our depressingly earnest theatrical climate, is staging Maugham’s “The Constant Wife,” a cheerful chip off the Wildean block. Written in the ’20s, Maugham’s comedy heralds a bottom-line modernism that never quite arrived. Those loose-moraled Continentals may have taken this sort of writing at its word, gadding about in open marriages, but on this side of the pond, matrimony is still a sacred cow. Marking the cow up for slaughter, checking its teeth and the sheen of its coat, still strikes us Puritan offspring as a bit shocking. Witness the self-righteous foam that our popular press can still work itself into when stars divorce.

Daring or not, “The Constant Wife” does seem like nostalgic decoration. Unlike “Being Julia,” the well-regarded film of Maugham’s novel “Theatre,”this play elects to ignore heartbreak and humiliation, the real by-products of marital renegotiation. “The Constant Wife,” while pushing the definition of marriage, still tastes like a dissolving meringue rather than a main course. Bless the Roundabout for staging it, though, as it exercises the impressive chops of some incredible actresses.

Kate Burton, as Constance, flits around her impressively appointed drawing room with a light heart and lighter heels. Allen Moyer’s gloriously ridiculous set, a green-and-gold reminder that taste at its highest levels can be actively painful, sets her off to perfection. The wallpaper, a riot of birds of paradise, got applause. So when we begin to first see Constance as a creature in a gilded cage and her best friend as a home-wrecking cuckoo, at least they match the decor.

Maugham stuck rather closely to the tenets of the well-made play, delighting in handkerchiefs, dropped cigarette cases, and some shockingly bald exposition. When we first meet Constance’s mother Mrs. Culver (Lynn Redgrave) and her spinster sister Martha (Enid Graham), it seems that Constance’s husband John (Michael Cumpsty) has been shockingly unfaithful to her, and the time has come to reveal all.

When Ms. Burton wafts in, she only perches, showing her legs to great ad vantage, and then whisks herself off to kiss another cheek. Accompanied by the bubble-brained Marie-Louise (Kathryn Meisle), who is both Constance’s best friend and John’s current mistress, our heroine manages to stave off all revelations her friends wish to force upon her. And when her mother, played with steamship momentum by Ms. Redgrave, waxes cynical about men, her daughter can top her. Comparing men to children and dogs, claiming they “don’t know enough to come out of the rain,” Constance seems to have nary a scale before her eyes.

Maugham doesn’t write a tale of female empowerment as much as he does one of mutual emancipation. If John could but see it, his wife offers him an even-handed, well-thought-out amendment to their marriage vows. Mr. Cumpsty, a handsome man with a primitive, beetling brow, goes from explosive good humor to apoplectic confusion as he tries to keep up with his wife’s plunge into the modern era. Everyone is shocked by her: When her various machinations come to light, her friends and prospective lover (a rather unimaginative John Dosset) sit and stand like astonished pistons. Constance is a champion manipulator, she is never at a loss or a disadvantage, which eventually makes her wearing company.

At the end of the two-and-a-half-hour production, the “Constant” wife has lived up to her name a bit too well. “Constant” – by George, she’s been Implacable. Director Mark Brokaw introduces moments of exquisitely timed physical humor, however, that keep our going light. Ms. Burton and Ms. Redgrave humor with a handkerchief; Mr. Cumpsty uses his ability to turn bright red to great effect. And when poor, cuckolded Mortimer(John Ellison Conlee) comes to confront his wife Marie-Louise, he manages to embrace his wife, a bouquet of hyacinths, and a chaise in increasingly ineffective order.

“The Constant Wife,” coming after this Tony spring of Mamet and Albee and Williams, does act as a refreshing sorbet. Sure, it’s a trifle, but one made with the topmost cream of our available acting crop. Ms. Burton, Ms. Redgrave, and Mr. Cumpsty cleanse the palate of all the heavy courses that have gone before, and they ready us for the season to come.

Until August 7 (227 W. 42nd Street, between Seventh and Eighth Avenues, 212-719-1300).