Blocking is a theatre term which refers to the precise movement an positioning of actors on a stage in order to facilitate the performance of a play, ballet, film or opera. The term derives from the practice of 19th Century theatre directors such as Sir W. S. Gilbert who worked out the staging of a scene on a miniature stage using blocks to represent each of the actors. (An example of this can be found in Mike Leigh's 1999 film Topsy-Turvy.)