Am-dram, thank you ma'am: the rise of good-bad theatre

Two very different theatrical territories – the London West End and the Edinburgh fringe festival – are currently united by their interest in bad amateur theatre. But this prospect is not as off-putting as it sounds, because – at least in the cases under discussion – the forgotten lines, malfunctioning props and unspeakable performances are intentional.

The production credits of this summer's West End shows include – alongside the regular big funders such as Sonia Friedman, Scott Rudin and ATG – two unlikely newcomers to London theatreland: the Bunbury Company of Players and the Cornley Polytechnic Drama Society.

With the inclusion of new scenes by the writer Simon Brett, the conceit of the revival of The Importance of Being Earnest at the Harold Pinter theatre is that Oscar Wilde's comedy is being performed by the Bunburys, a group of amateur theatricals in the shires. There are many theatrical examples of plays within a play, but Brett's additional text is a rarer instance of a play outside a play (others include Stoppard's Rosencrantz and Guildenstern Are Dead).

A similar concept has the Cornley Polytechnic Drama Society notionally putting on a production of a 20s murder mystery in The Play That Goes Wrong, which arrives at London's Duchess theatre in September after earlier successful runs at the Trafalgar Studios, the Edinburgh festival and on a UK tour.

A play that goes wrong – the premiere of Romeo and Juliet – is also the subject of Shakespeare in Love and, in the PG Wodehouse hit Perfect Nonsense, now on its third West End cast, the premise is that Bertie Wooster has hired a theatre to dramatise an anecdote, with Jeeves required to be set designer, props master and co-star.

Similarly, although the long-running The 39 Steps does not use the trope of an amateur theatre company, its running joke about telling an epic story with a cast of only four results in many of the same gags about quick-changes, or an actor suddenly realising he is playing both parts in a dialogue.

As a result, the West End is currently offering five different productions about the pitfalls of live cheap theatre, and a sixth has just closed: Handbagged, Moira Buffini's comedy about the relationship between the Queen and Margaret Thatcher, divided dozens of other parts between two men, seeding a running gag involving the actor's nightmare of being in the wrong place or character at the wrong time.

Further north – for reasons that any veteran Edinburgh-attender will appreciate only too well – theatrical disasters are often the deliberate subject, rather than the accidental consequence, of shows brought to the fringe. This year, they include Actors by the Chicago-based Underscore Theatre Company, which is set just before curtain-up on a performance of Hamlet in which the main cast are either incapable of speaking on stage or no longer on speaking terms off stage.

Also appearing this year, as part of the 2014 repertoire of the American High School Theatre Festival, regular visitors to the fringe, is The Actor's Nightmare, a much-revived 1981 short play by the US dramatist Christopher Durang, in which an accountant is mistaken for the understudy of an unwell frontline actor and pushed on stage without rehearsal.

Clearly, the main reason audiences enjoy watching productions in which things deliberately go wrong is that one of the secret pleasures of theatre-going is seeing things accidentally going wrong. This risk is part of the appeal of live performance and – although audiences are generally generous to performers when a gun doesn't fire or a door gets stuck – such kindness may be a compensation for the guilty hope that there will be some kind of onstage mishap.

There are inevitably many overlaps between the numerous playing-with-plays shows mentioned above, because there are only so many ways a performance can go wrong: actors, props, sets or audiences failing to arrive or perform as hoped. Another recurrent element in these attempts to make good drama out of bad theatre is the suggestion that the company's ambition has been larger than its talent.

In that sense, all onstage or backstage comedies are in some way indebted to two modern classics of anti-theatre: The National Theatre of Brent – created in 1980 by Patrick Barlow – and Michael Frayn's 1982 play Noises Off.

The joke of Brent was that Barlow and one accomplice (a part taken by Jim Broadbent and John Ramm, among others) act out two-man, low-budget versions of epic narratives including Handel's Messiah and Wagner's Ring Cycle. In Frayn's masterly farce, a touring company – theoretically professional but in practice amateurish – struggles through a matinee performance in Weston-super-Mare of the fictional sex romp Nothing On.

The influence of either or both shows can be seen in most subsequent theatre sendups. The mad folly of Wooster in Perfect Nonsense is very Brentish, and the scenes in Shakespeare in Love that flip the stage-picture – so that Romeo and Juliet is alternately seen from the perspective of an audience and the performers in the wings – reflect Frayn's rotation of the view in Noises Off.

Brett's framing device for The Importance of Being Earnest learns several tricks from Frayn, including a spoof inset for the programme, with mock biographies of the fictional actors and the addition of a comic undercurrent to certain scenes, due to the audience's knowledge that the fictional performers are having an offstage affair: in this case, the Bunbury players cast as Algernon Moncrieff and Cecily Cardew.

The biggest problem for professional theatre about amateur performance is the need for actors to decide how bad at acting their characters will be. This isn't a problem in Perfect Nonsense – where Wooster is being himself and it is exactly in character for Jeeves to turn out to be an unexpectedly talented actor – or in Shakespeare in Love, because there the narrative involves the writer and actors overcoming disaster to put on the play we now have as Romeo and Juliet. However, in The Importance of Being Earnest, the external production is undermined by uncertainty about how good or bad the internal production is supposed to be.

The extra scenes written by Brett suggest that the lecherous hotelier Dicky Oldfield would be a rather bad Moncrieff, but he turns out to be a rather good one, largely because he's Nigel Havers. And Siân Phillips seems more or less to forget the conceit and simply deliver an impeccable Lady Bracknell. You could argue, I suppose, that am-dram is often played to a high standard, but the oddness of watching a jokily ropey theatre company give a pretty decent account of Wilde's play makes the evening uneven.

In theatre about theatre, directors and actors have to have a counterintuitive discussion: how bad is this production supposed to be?