The A4 is part of the family of what improvisers call the middle-form because each improvisation lasts 20 minutes. 4 players will build 4 stories based on sentences drawn from books with the collaboration of the public and the master of ceremonies. Long improvisations give constructed stories where characters arise and develop to bring unpublished situations. Come and discover this format that will give you another image of theatrical improvisation. A proposal La Lipho, Phocaean improvisation league.