Sarah Kane
Always ready with a capricious stage direction ... Sarah Kane. Photograph: Jane Bown

British theatremakers have a curiously paradoxical attitude towards the plays they produce. It is often said that we have a culture which is slavishly subservient to the text - that the job is to serve the writer's vision and not impose anything on top of this. And, with some notable exceptions like Katie Mitchell or Emma Rice - whose work often has a clear directorial signature on it - this is a fair description of most directors' attitudes.

There is, however, one notable area where writers' intentions are frequently ignored - their stage directions. Whilst dialogue is sacrosanct, all the playwright's other notes about a character's actions, emotional state or the setting of a scene are often seen as at best optional, and at worst, things to be actively ignored.

There are a number of reasons for this. It is partly historical - after all it is widely assumed that most stage directions in Shakespeare are not the author's own (though some may have been added by colleagues) and therefore not authentic. And sometimes, as in most Samuel French playtexts, the stage directions in a script are little more than a record of how the play was originally staged.

Yet for many actors and directors, there is a more fundamental reason for ignoring these authorial notes - they are seen as an attempt by the writer to muscle in and do their job for them. And some writers even seem to agree with them - Tom Stoppard recalls having spoken with one young playwright at a workshop who described stage directions as "fascist".

This is an understandable view. But I often find, when reading plays, that a good writer can not only communicate an enormous amount in that italicised text between the characters' speech, but that, in some circumstances, the more demanding the stage directions, then the more creative freedom that the director has. Take Sarah Kane's work. In Cleansed a couple make love and we are told "a sunflower bursts from the floor and grows above their heads"; at another point, she describes with dry wit how one character - Tinker - punishes another: "He takes Carl by the arms and cuts off his hands... Carl tries to pick up his hands - he can't, he has no hands."

When Kane wrote these moments she joked that she did so in order to "punish" the director James Macdonald. But elements like this are so clearly impossible to realise literally that they force the creative team to be, well, creative.

There can also be real poetry in a play's stage directions. Look at Gary Owen's Cancer Time. It tells the story of two squabbling welsh secretaries Iola and Marad whose husbands are both serving in Iraq. The piece has a surreal tinge which is no more obvious than at the end of the play when Marad's husband has been killed. As the two sit on a patch of grass outside their office, considering what has happened, we are told:

They sit. And gradually, the day turns to night. They sit. And gradually the summer turns to winter. They sit. And gradually the city disappears beneath grass and wild flowers. They sit. And gradually the buildings all crumble to the ground.

It is an extraordinarily beautiful final moment, but one that is surely not meant to be taken literally. Rather, what Owen is doing is vividly signalling the depth of the characters' mutual bond, and challenging the director to find a way of expressing this equally as eloquently on the stage.

In a similar vein is one of the final stage directions in David Greig's playPyrenees. Vivienne, an older woman has been finally reunited with her long-lost, amnesiac husband. As they sit and eat dinner, Greig tells us:

There is a moment in which they experience many emotions. None of which they express.

The moment passes.

It is a sublime observation and one that, whilst inherently unperformable, still provides an absolute gift for an actor seeking to understand their role.

None of this means that directors should approach all stage directions as if they had been written by Beckett. But they can, in the right hands, provide the key to realising a production.