In the mid-1970s Chapman was appointed to the Royal Court Theatre, London, in charge of the Young People's Theatre Scheme. This had originally been set up in 1966 to develop and produce the best new writing by young people under 25, encouraging writers from all sections of society to find their voice. In 1976, as part of a drive to invigorate the group, Chapman developed the YPTS idea and held a competition to give the group a shorter and snappier name. The winning name chosen was "The Activists"; the logo of which was the letter "A" formed of nails, to signifying the driving edge and hard grittiness that typified the group's work. This group had two main branches of activity – the first was a mainstream group that worked with influential writers and directors such as Edward Bond, John Schlesinger, Max Stafford-Clark and many others. The second group was formed as part of an offshoot of the radical theatre company Gay Sweatshop, with which Chapman had worked previously. Together with South African writer David Lan, workshop sessions were held with a group of gay teenagers to develop a play that would eventually become a touring production called "Not in Norwich" (see the following web-link). This highly controversial show (for the time) aroused deep press hostility, which resulted in a front-page story in the London "Evening Standard": "London Children in Sex Play". In contrast to the sensationalist press stories (the play actually contained no sexual scenes whatsoever, and the so-called "children" were all, at the time, actors in their late teens), the play itself was constructed from the real life personal experiences of young British gay teenagers, containing as it did, examples of the difficulties, prejudice and considerable humour of those that took part. The Royal Court, through Chapman and then director Ann Jenkins, fought against a largely hostile press to maintain the integrity of the production, which successfully played at the Royal Court as well as on tours to regional theatres and schools. It was pioneering work of this kind that became a hallmark of Chapman's career, before it was cut so tragically short in 1987. He also taught school, ran workshops, and organised the highly successful Young Playwrights' annual festival.