Devised Work, or Improvorama
What the heck is Improvorama? You could use the terms original, organic, ensemble-based, and collaborative to describe the process of Improvorama.
Improvorama shows are devised original theatre and start from a simple idea for a show, or desire to investigate a particular work or author. Ensemble members are selected after the theme or idea is selected. Then the idea is improvised until an outline for a script emerges. The script continues to be developed until it is ready, or until time runs out. The process is driven by generative energy and is performer conceived.
Sure there is more to the process, but all of that happens in the rehearsal room, and is tailored to the needs and goals of the individual production.
Productions strictly devised and developed by Carrie Klewin with Improvorama include, A Christmas Catastrophe, Aladdin, and Tempest4.