Every critic has had the experience of seeing their words tweaked for the purposes of an advert – and many of us have seen them ruthlessly taken out of context. I once ended a review of Saturday Night Fever by saying: “If it’s an all-out retro romp you’re after, this only fitfully delivers.” It reappeared in the show’s publicity as “an all-out retro romp!”. Which was only a step away from changing “whatever you do, don’t see this show” to “see this show!”.

Theatre producers need brisk, brash quotes to help to sell shows. To some extent, fair enough. Unless reviewers restrict themselves to barking out no-grey-area utterances such as “codswallop!” or “Michael Crawford proves himself our greatest performer since Churchill!”, there will always be some gentle tweaking to the production’s advantage.

But if theatregoers are offered opinions edited to the point of a 180-degree change of meaning, it’s a rip-off, plain and simple. When the critic David Benedict reviewed Gyles Brandreth’s musical Zipp! for the Independent on Sunday, he wrote: “If schoolboy innuendo is your bag, book now.” The edited version for the theatre hoarding? “Book now – The Independent on Sunday”. “I was fairly furious,” says Benedict, “because as a critic your opinion is what gives you currency. If someone goes and sees a show because they think you’ve recommended it, and it turns out to be junk, that’s very damaging.”

This month The Daily Telegraph critic Dominic Cavendish reviewed Joe Penhall’s play Landscape with Weapon at the National Theatre. “If anyone was going to produce a scorching, blinding, lacerating play about the arms industry, I’d have put smart money on that someone being Joe Penhall,” wrote Cavendish, before mourning the fact that this show doesn’t actually pull it off. The quote as the National run it? “A scorching, blinding, lacerating play about the arms industry.”

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