The 180 degree rule is a filming technique that keeps the camera on one side of an imaginary line between two subjects in a scene. Crossing this line, or breaking the 180 degree rule, can cause confusion for viewers as the spatial relationship between characters appears to change. Basic rules require characters to maintain the same left-right relationship. Examples show this rule applied to car chases and interactions between actors. Match on action is a continuity editing technique where shots are edited together to make an action, like opening a door, appear fluid and continuous.

1. 180 Degree Rule
A rule stating that a camera should be placed somewhere inside 180
degrees on a particular side of the invisible line of a shot containing
two people filmed in sequence. If the camera crosses the line it
means you’re breaking the 180 degree rule and so, confusion results
for the film viewers, because it makes it look like the people are
switching places as one watches the film.
Rules of the 180 degree rule
Basic rules meant that two characters should always have the
same left and right relationship to each other.
The camera crosses the axis connecting two subjects, where it
called “Crossing the line” and where a new shot is called the
reverse angle.
Examples of the 180 degree
rules
The 180 degree rules are normally shown in Car chases. So if
the car leaves the frame of the right side, in the next shot it
should be on the left side.
This image on the next slide represents the 180 degree rule in a
relationship between two actors.

2. Match on action
Match on Action-Match on Action is a continuity editing technique.
For example, it can involve a person opening a door like in the video
presentation of Match on Action that we have also made for our
“open door”. This can be done in three simple shots; One to show
the person walking towards the door, another shot zoomed on the
person’s hand on the door, and the final shot to show the person
coming through on the other side. These shots are all then edited
together to make it look continuous and as if it is all happening
fluently and naturally. This technique can be done with any action, it
is just to portray a false sense of continuity to the viewer.