Those who can, create theatre and those who can’t, become drama critics - as George Bernard Shaw, himself a seasoned reviewer, didn’t quite say. But as both fields of journalism and theatre are increasingly threatened today, I feel that we need to define our role. So who are we and what, if any, is our role in the industry today?

The first question is the easier one. We’re earnest folk who sit in theatre seats with note books and pens juggling a plastic glass of wine. Along with a complimentary ticket, a free drink is often our only little perk. And what is the essential experience needed for the job? Well, only one fundamental skill is required: the ability to write in the dark, clearly enough to be able to read it back a few hours later. It's more challenging if you’re tucked away in the stalls at Theatre Royal Drury Lane than at Park200 where the current production of Holy Fool floods the audience with as much light as the action.

If our reviews attract enough gush they are plastered all over the show’s posters and hoardings. But the trouble is, we’re a picky lot and will often criticize, if not, castigate a show. I myself am actually banned from one small theatre because I once had the temerity to criticise a production rather than raving about it. But after all, that is what competent critics do – the clue is in the job title.

It is true that reviews can sometimes make or break a show. But it’s worth remembering that when Les Miserables opened at The Barbican in 1985. Lyn Gardner called it “a load of sentimental old tosh”, Michael Ratcliffe for The Observer found it “trivialising” and The Daily Mail’s Jack Tinker nicknamed it “The Glums”. But 41 years later? Sometimes the public simply makes up its own mind.

I’ve interviewed dozens of actors who tell me loftily that they don’t read reviews – although I bet they do. Others, the particularly needy, anxious sort, usually ‘emerging’ rather than established in show biz, are sometimes so uptight about their work that they feel miffed if not mentioned by name in the review. I was privately approached via my website only last week by one such asking me for “feedback” on her performance. She didn’t get it. Once a review is written and published “no further correspondence will be entered into” – like an old fashioned radio or TV competition.

You have to be resolute in this job. You need also to be able to keep your head when all about you are losing theirs (thanks, Kipling) because it matters not a jot what anyone else thinks. You have been invited to the show to report what YOU think. That’s why, when you meet other critics – many of them people you’ve known for years – over interval drinks or on the bus home, it’s wise not to discuss tonight’s show. And never, never, must you read anyone else’s review before you’ve written yours.

Critics are a valuable cog in the big complex wheels which keep the industry rolling. Whether you’re a veteran (and I’m afraid I’ve probably seen Macbeth and The Mikado in fifty different productions over the years) or new to reviewing, you bring fresh eyes, ears and have a part to play.

People – producers, directors, performers – want to know what you think. It’s not a second-best job.