Units of Action, or Units (sometimes also called beats) were first suggested by Konstantin Stanislavski as a means of helping actors determine the through line or super objective of a role. A unit is a discrete piece of action in a play-text, marked by a significant change in action. This could be a change in what the characters already onstage are doing or trying to do i.e. a change in their objective, a new character entering the scene or those already onstage exiting. Units are also used by writers and dramaturges as a means of analyzing text for editing purposes. Dividing text into units makes it more manageable and thus easier to edit.
Unit of action is also a physics term describing things of units in reduced planck constant.
