Retroscripting

Improvisational theatre, often called improv or impro, is the form of theatre, often comedy, in which most or all of what is performed is unplanned or unscripted: created spontaneously by the performers. In its purest form, the dialogue, action, story, and characters are created collaboratively by the players as the improvisation unfolds in present time, without use of an already prepared, written script.

Improvisational theatre exists in performance as a range of styles of improvisational comedy as well as some non-comedic theatrical performances. It is sometimes used in film and television, both to develop characters and scripts and occasionally as part of the final product.

Improvisational techniques are often used extensively in drama programs to train actors for stage, film, and television and can be an important part of the rehearsal process. However, the skills and processes of improvisation are also used outside of the context of performing arts. It is used in classrooms as an educational tool and in businesses as a way to develop communication skills, creative problem solving, and supportive team-work abilities that are used by improvisational, ensemble players. It is sometimes used in psychotherapy as a tool to gain insight into a person's thoughts, feelings, and relationships.

The earliest well documented use of improvisational theatre in Eastern history is found in the Atellan Farce of Africa 391 BC. From the 16th to the 18th centuries, commedia dell'arte performers improvised based on a broad outline in the streets of Italy. In the 1890s, theatrical theorists and directors such as the Russian Konstantin Stanislavski and the French Jacques Copeau, founders of two major streams of acting theory, both heavily utilized improvisation in acting training and rehearsal.

Modern theatrical improvisation games began as drama exercises for children, which were a staple of drama education in the early 20th century thanks in part to the progressive education movement initiated by John Dewey in 1916. Some people credit American Dudley Riggs as the first vaudevillian to use audience suggestions to create improvised sketches on stage. Improvisation exercises were developed further by Viola Spolin in the 1940s, 50s, and 60s, and codified in her book Improvisation For The Theater, the first book that gave specific techniques for learning to do and teach improvisational theater. In the 1970s in Canada, British playwright and director Keith Johnstone wrote Impro: Improvisation and the Theatre, a book outlining his ideas on improvisation, and invented Theatresports, which has become a staple of modern improvisational comedy and is the inspiration for the popular television show Whose Line Is It Anyway?

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