All Savoyards, whether conservative or liberal towards productions, have been grievously practised upon. They told us to expect the first professional London grappling with Gilbert and Sullivan’s eighth and, subject-wise, most problematic operetta in 20 years (23, if the reference is to Ken Russell’s unmitigated mess, one of English National Opera’s biggest disasters). Yet this is not Princess Ida as the pair would recognize it.

Joshua Harmon’s provocative 2012 piece is the Rocky of comedies. His evenly matched sparring partners, a pair of viscerally antagonistic cousins confined in close quarters after a familial loss, bruise, bludgeon and literally draw blood. The bonds of kinship have never felt so tangible, so knotty, so inescapable.

The seasonal family reunion play is a hardy perennial. Like the Christmas tree that must take its place on the stage, it is usually spiky, dry and decorated with glittering ornaments – as in acidic jokes, acute embarrassments and ghastly revelations. Into every yuletide family a stranger must come, and all the most careful preparations must be ruined. Normally, everyone gets drunk, food gets thrown and truths get told. But if these are the rules of the genre, how does Sam Holcroft’s new drama bend them, and play with them?

If insanity is doing the same thing over and over and expecting different results, repeatedly unfunny Harvey isn’t just a study of madness, but a punishing example of it. Mary Chase’s dusty 1944 farce about a man hallucinating a 6ft 3in rabbit has slapstick trappings, but, in Lindsay Posner’s flat revival, the pace and energy of a straggling funeral procession.

There can be few modern plays as testing for a female actor as Manfred Karge’s Man to Man. When Tilda Swinton took it on at the Royal Court in 1987 and brought to the many roles of this one woman show her androgynous intensity it was the performance that made her name. Here in Cardiff for the Wales Millennium Centre’s revival, Margaret Ann Bain gives one of the most tireless and faultless performances a Welsh stage has seen in some time; a breathless, kinetically poetic 70 minutes that is never anything less than entirely captivating.

Stephen Sondheim's ever-elastic masterpiece is downsized to largely dazzling effect in its latest iteration, which has been transferred intact to a Shaftesbury Avenue pop-up after premiering last autumn within the surrounds of an actual pie-and-mash eatery called Harrington's in Tooting, south London.

Hey, it’s the 1990s – yet again. After high-profile revivals of contemporary classics, such as Patrick Marber’s Closer and Kevin Elyot’s My Night with Reg, here comes, from that edgy decade, a fringe version of the iconic story of Leith heroin addicts, based on the cult book by Irvine Welsh which spawned a classic 1996 film by Danny Boyle, as well as this play, adapted by Harry Gibson in 1994. This version of the in-yer-face drama by the aptly named In Your Face Theatre Company was first seen at the Edinburgh Festival last year. How well has it traveled south?

This 1887 domestic drama by August Strindberg is rarely seen in London, and Abbey Wright’s new production of Laurie Slade’s new version might have seized the opportunity to give this gristly chunk of pre-Freudian sexual polemic a thorough 21st-century shake-up. That chance is missed.

This is, stresses our guide, a work of pure (read: non-libellous) fiction, except that its “preposterous” premise is rooted in even more preposterous truth. In 2010, diva extraordinaire Barbra Streisand produced wildly narcissistic coffee-table book My Passion for Design chronicling the creation of her gaudy Malibu dream estate, which – gloriously – includes a basement storing her extravagant collections in fully-fledged “shoppes”. What, pondered writer Jonathan Tolins, would it be like if someone had to work in this absurd consumerist utopia?

Jacobean playwright John Ford is flavour of the season at the Sam Wanamaker Playhouse. His better-known, and simply better, ‘Tis Pity She’s a Whore, opened the venue’s new programme last autumn and is followed now by that work’s younger sibling, The Broken Heart, in a production that rather gloriously surprises.