Equus was written by Peter Shaffer in 1973 and premiered at the Old Vic, London, in July of that year. It is based on the true events of a 17-year-old boy, Alan Strang in the play, who, having blinded six horses at a Norfolk livery stable, was sent to a paediatric psychiatrist to be assessed for a mental illness. Shaffer said after hearing the story he wanted "to interpret it in some entirely personal way", with his dramatic goal being "to create a mental world in which the deed could be made comprehensible."
Due to the sexual nature of the subject matter and use of profane language, the producer has put a lower age limit of 15. Younger teenagers, from 13, will require written parental consent or be accompanied by a responsible adult over the age of 18.