Editing: 180 Degree Rule

The 180 degree rule is the principle by which the camera can only film two characters on one side of an imaginary axis that is situated through the centre of both characters, assuming they are sat opposite one another. Breaking the 180 degree rule can cause confusion, it creates the illusion that the two subjects are facing the same direction, causing a scene to appear distorted. Depicted below is an illustration of the intangible confine of the axis that governs the 180 degree rule.

In more complex cases, when characters are moving, the order/direction in which they enter the frame of the camera is imperative in order to ensure the audience comprehends the sequence of events. For example, if the director wishes to convey an extended amount of time passing, a character exiting the frame on the left before entering the frame from the left in a new environment will give the effect that an extensive period of time has passed. The video below explains the concept behind the 180 degree rule in further detail.