SHAKESPEARE SCHOOLS DRAMA FESTIVAL. Various venues until October 12.

The best ideas arrive in the strangest places. Ten years ago, Chris Grace, director of animation at S4C (the Welsh fourth television channel), was responsible for a series of films from Shakespeare’s plays. Made at studios in Russia, using a variety of animation techniques, the Animated Shakespeare series proved a tremendous success and has been used in 90 per cent of British schools; it is the BBC’s most successful education series.

Then, on millennium night, Grace was on holiday in Sarawak, Borneo, when a thought from “somewhere at the back of my head” suddenly gelled. One or two schools had asked if they could use the scripts of the Shakespeare films for drama productions. Why not bring several schools together and get them to perform for a wider audience?

Once he has a good idea, Grace is not the sort of person to sit on it. Back from the jungle, he contacted Gerson Davies, director of education in his home county of Pembrokeshire, and by early October 2000, 12 to 15-year-olds at eight local schools were putting on the Animated Tales to packed houses. “There were some extraordinary performances,” Grace says.

This month, the Shakespeare Schools Drama Festival comes to three venues in London: Greenwich Theatre, Stratford Circus and Questor’s Theatre, Ealing. Children from 63 inner-London schools are involved in productions of a dozen plays. On Sunday, November 25 - long after the festival has finished - four schools will perform at a special gala evening in the Duke of York’s Theatre, although Chris Grace emphasises that this will be a celebration, not a competition.

The festival retains strong links with the original films. It is being administered by Right Angle, the team that co-ordinates S4C’s animation projects. The 12 plays (all to be performed at each of the venues) are the same as those in the two series of films. They include The Tempest, Hamlet, A Midsummer Night’s Dream, Othello and Macbeth. The scripts are those written by the late Leon Garfield for Animated Shakespeare. Garfield reduced the action of each play to about half an hour and cut out some minor characters and sub-plots, but retained as much as possible of the original language.

When the films were first shown on television, some critics had reservations about the cuts, but time has proved them wrong: schools using the series have found that it achieves its objective, which is to provide an introduction to the plays and a bridge across difficulties of language, length and plot.

The casts have had since August to learn their lines; the schools get only four to five weeks to rehearse. All the teachers involved in directing the plays have attended one-day workshops run by members of the Royal Shakespeare Company. The cast in each school has had a half-day workshop with Kate Allerston and Phillip Gates of Dramarama, a theatre-in-education company set up with help from the Prince’s Trust.

At Dramarama’s visit to Thomas Tallis school in Kidbrooke in the London borough of Greenwich, the workshop was being filmed for a Channel 4 schools documentary on the festival to be broadcast next year.

The Thomas Tallis group - a dozen bright pupils from Years 7 to 10 - are rehearsing Twelfth Night for next week’s performance under the direction of English teacher Dan Shaw-Stanley. Kate and Phillip begin by getting the children to talk about their characters and the main themes of the play, then do a series of exercises to help them project their voices and emotions on stage. “You’re now actors in a theatre company,” Kate tells them. “You have to get rid of all that inhibition.” By midday, they are exploring the rhythms of Shakespearean verse and telling a simple story in iambic pentameters.

They are encouragingly positive about their forthcoming performance and have clearly already gained confidence from working on the play. “It’s going to be good,” one of the players promises. “I didn’t much like Romeo and Juliet in primary school, but I like Twelfth Night.” As not all the schools are mixed, the productions on offer include at least one all-girl Hamlet.

Quinton Kynaston school, in the London borough of Camden, was planning a Romeo and Juliet which drama teacher Graham Contor promised would be “very urban, very contemporary, with a sense of cinema: we’re dressing them like Dick Tracy characters”.

Chris Grace’s dream is to see this become a biennial festival, “so that kids in Years 7 to 10 get a chance to do it twice, and so that we can make it into a feature in the schools calendar”.

Anyone who manages to get a ticket alongside the actors’ parents is sure to be impressed by the standard of the performances. And what appears on stage is only the start: the real value of the exercise will be the experience the participants take away with them.

The Shakespeare Schools Drama Festival is at Greenwich Theatre tonight and October 8-12 (tickets: 020 8858 7755); final performances tonight at Stratford Circus (020 8279 1000) and Questor’s Theatre (020 8567 5184), with the Thomas Tallis Twelfth Night on October 12