Classical unities

The classical unities, Aristotelian unities, or three unities represent a prescriptive theory of dramatic tragedy that was introduced in Italy in the 16th century and was influential for three centuries. The three unities are:

1. unity of action: a tragedy should have one principal action.
2. unity of time: the action in a tragedy should occur over a period of no more than 24 hours.
3. unity of place: a tragedy should exist in a single physical location.