He was born in Devon, England in 1933. From 1956 to 1966 he worked as a director and acting teacher at the Royal Court Theatre in London. After negative experiences during his own training, which he had found to be fantasy killing and intimidating, he tried to incite his actors to be more spontaneous by negating all the rules he had learned in his training. For example, he encouraged them to grimace on stage and get angry in a playful way; he instructed them to not concentrate, not to think and to do the obvious. When he saw that these techniques were successful - the actors played more freely and with more joy - he developed theatrical principles from them.
- Johnstone, Keith: Impro: Improvisation and the theatre, Theatre Arts Books, 1979. ISBN 0878301178
- Johnstone, Keith: Impro for Storytellers, Routledge; 1st edition 1999. ISBN 0878301054