Many of us know who the culprit is in The Mousetrap. But it would probably take the Spanish Inquisition to get the information out of us – we know that it would be plain bad manners. But when it comes to talking or writing about a theatre experience, it strikes me that thrillers with a crucial plot twist are the exception rather than the rule.

Knowing that Beatrice and Benedick eventually get together never put anyone off going to see Much Ado. And I've never heard anyone say that they aren't going to see Hamlet on the grounds they know what happens. The formula of the romcom, or the Jacobean revenge tragedy set up expectations that those plays then fulfil – and, sometimes, subvert. It is, you could argue, part of the pleasure.

Like any other theatregoer, I'm aware of the pitfalls of knowing too much: it's the reason I prefer not to review shows if I've done an interview ahead of time, or written a preview feature about them. The director or playwright has already shared her or his intentions with me. But in that instance it's because the danger is that you review what you have been told about the show, rather than what you actually see.

Yes, surprise in the theatre – whether it's in terms or narrative or something more visceral or visual – can be a real pleasure, and it would be a pity to spoil the delight or shock of such moments. There are two extraordinary visual images towards the end of Metamorphosis, currently at the Lyric Hammersmith, in west London, which give the production a shocking historical perspective. I judged it better to allude to them in my review, rather than spell them out, but, in fact, seeing the production a second time and knowing what was to come actually deepened my experience rather than lessened it.

It's increasingly common for audiences to be asked on leaving a show not to divulge what happens. Yet I'm inclined to think that leaving the issue of spoilers to the judgment of critics and audiences is far better than pressuring them into secrecy. The more robust a piece of work, the more likely it is to withstand spoilers. The entire structure of most Greek tragedy is geared towards creating an unbearable tension in an audience which already knows what is going to happen. Modern comics understandably get upset when reviewers give away great jokes, but in a pre-TV era audiences loved knowing the routines of the music hall stars. It was the familiarity – and supreme delivery – that they cherished.

My impression is that theatremakers and audiences get more upset about spoilers than they did in past, but I'm not sure whether that's simply because the range of information, previews, comment and review is much more extensive than it was. Or maybe it's because more theatre shows are aping the visceral thrill of a fairground ride, and know that surprise is their greatest – and possibly only – weapon.