All of my students are required to read this. It is one of the most highly reccomended books regarding improvisation and long form there is. It is regarded as the primer for learning longform, and I whole-heartedly agree. Read it, love it, live it

More from Viola. This book contains interesting games for young and old students alike.

2nd in his series on acting

Keith Johnstone is one of the few published improvisers of our time without roots in Chicago. His ideas on improv, though differing in their presentation, reinforce many things taught in Chicago and in other centers of improv around North America. A good read that should put perspective on what you already know, and enlighten you to somethings you didn't.

One of the most controversial texts on acting of our time. Mamet has some wonderful and cruel things to say about the actor, and the process. His ideas for the stage and screen run very close to the axioms of the improv moment.

The grandmother of improv as we know it today. Her work, and the continuing work of her son, Paul Sills, has given the improv bug to many improvisers of the past and today, including Del Close and Sue Stephens.

Stanislavski, best known for "The Method" has a great insite into character and it is very well articulated throughout his works. His discussions on the physicality of a character and using character emotion are very enlightening.

3rd and final book in the series

What he began in Impro for the Theater, he takes up again and expands in this book. Johnstone has some great ideas.