The Cherry Orchard, NT Olivier, London<br/>School for Scandal, Barbican, London<br/>The Merchant of Venice, Royal Shakespeare Theatre, Stratford

A telegraph pole stands downstage left, its wires stretching into the distance.

On Madame Ranyevskaya's country estate, the old wood-panelled nursery has been fitted with electric light, and a telephone rings in a corner. This is not your traditional image of The Cherry Orchard.

Neverthelesss, directed by the NT's Russian specialist Howard Davies, this production is no crass update. As designed by Bunny Christie, it's in fact a pretty scrupulous period production of Chekhov's great portrait of time running out for Russia's landed gentry.

Zoë Wanamaker's Ranyevskaya wears belle époque finery: a compulsive spendthrift still not facing up to her chronic debts. The telegraph wires emphasise how Russian society, circa 1904, is succumbing to modernity – not just in industrial advances, but also in entrepreneurialism and social equality. Yes, the changes have been happening here faster than you might expect. Conleth Hill's Lopakhin is a sharp-suited second-generation businessman, urging Ranyevskaya to sub-divide her ancestral acres into holiday-home lots. In the last act, the sound of her beloved cherry orchard being axed sounds like an inexorably ticking clock, with the Russian revolution imminent, of course.

Andrew Upton's new English version takes occasional liberties with the text and includes some obtrusively present-day phrases. Then again, that helps you see the through-lines of history. Mark Bonnar as the proto-revolutionary Trofimov preaches with exhilarating vigour against fat cats, advocating a new freedom to be gained through radical anti-materialism.

This production is not, perhaps, as brilliantly revelatory as Davies's revivals of lesser-known Russian classics. I have seen more heartbreaking Cherry Orchards, and Wanamaker's longest speeches look too much like set pieces. But elsewhere her Ranyevskaya is charmingly funny and impulsive, almost skipping around with a nervous energy that conceals repressed griefs. Well worth catching.

Regrettably, the same can't be said of Deborah Warner's dismally lame School for Scandal. On re-reading Sheridan's 18th-century satire, its topicality leaps off the page. A bunch of high-profile public figures indulge in closet affairs with each other or their domestic staff, in lavish spending and uncontrolled boozing. Most of them also make it their business to ruin others' reputations, obsessively exchanging sniping gossip as the press try to keep up. A few, embroiled in this, start wishing for gagging orders.

In theory, then, Warner's concept ought to be a winner: a period-costume production with contemporary spin. Matilda Ziegler's Lady Sneerwell and her coterie look like fashion-industry poseurs going through a fancy-dress fad. Donning pannier skirts over sneakers, they launch into catwalk struts between scenes, accompanied by rock music and computer-generated projections – a swirl of Sheridan's aptronyms.

But Warner hasn't fully thought through her updating, and the snazzing-up is superficial. Worse, in a convoluted plot, several characters lack focus. Aidan McArdle renders smooth-talker Joseph Surface as merely stiff and dull, and the farce of amours and jealous husbands, stashed behind screens and in closets, falls flat.

Hey ho. At least Alan Howard and Katherine Parkinson bring out the affection that runs deep under Lord and Lady Teazle's marital squabbles. And Leo Ringer somehow manages to be likeable as the debt-ridden, booze-swilling youth Charles Surface, even as he dashes around like a manic junkie auctioning off his inheritance.

In the RSC's Merchant of Venice, Patrick Stewart's Shylock is demanding the insolvent Antonio's pound of flesh, as payback for remorseless scorn.

Director Rupert Goold has translated the action to a modern, fantasy-tinged Las Vegas. Here Scott Handy's Antonio – a Wasp trader with druggy associates – gambles in a glittering casino owned by Shylock. Meanwhile, Susannah Fielding's Portia – a billionaire valley girl – is stuck with her casket-guessing suitors in a TV game show called Destiny.

This is audacious and inspired. Ye olde fairytale caskets scenario, with that satiric twist, proves hilarious, and the production darkens poignantly.

The US setting may seem an odd choice for Shakespeare's play about dire Christian-Jewish relations. But Goold is really developing a picture of a multicultural society riddled with xenophobia in various forms. When the cameras stop rolling, Fielding's Portia is horridly racist about her black suitor and dismisses the Hispanic one.

When robbed of his daughter, Jessica, Stewart's dignified Shylock becomes a broken man, then vengeful with a touch of dementia. But this Merchant is ultimately Portia's tragedy. Ditching her dumb blonde act and turning smart lawyer, she saves Antonio – her husband's buddy – only to find these men love each other more than her.

'The Cherry Orchard' (020-7452 3000) to 28 July; 'School for Scandal' (0845 120 7550) to 18 Jun; 'Merchant of Venice' (0844 800 1110) to 26 Sep

Next Week:

Kate Bassett sees the latest Pygmalion

Theatre Choice

Edward Albee's dysfunctional drawing-room drama, A Delicate Balance, is satirically droll, with a dreamlike surreality. In James McDonald's gripping production at London's Almeida (to 2 Jul), Penelope Wilton (Agnes) and Tim Pigott-Smith (Tobias) star with Imelda Staunton as Agnes's booze-sodden, accordion-playing sister.