Impro — Keith Johnstone (1979)

Keith Johnstone. Impro: Improvisation and the Theatre. Faber & Faber, 1979.

The foundational text of modern improv pedagogy. Introduces the offer/accept/block framework, status transactions, spontaneity vs. planning, and the principle that drama is about one person being changed by another.

Key concepts originating here:

Referenced by atoms: accepting-the-offer, offers, status, blocking, be-changeable, obvious-choice, yes-and