180 Degree Rule!

Continuity is a big part of film making. If you're shooting a short film or interview, it's important to set the scene and establish your characters in space and time in order for the viewer to follow the action. One of the most basic continuity rules is the 180 Degree Rule. 

The 180 Degree Rule states that two characters in a scene should always have the same left/right relationship to each other. If you don't follow the 180 Degree Rule, or break it intentionally, it disrupts the scene disorients the audience. When you break the 180 line, a person who was originally facing left in a scene is all of the sudden facing right. Wait! When did they switch places?

The 180 Degree Rule enables the audience to visually connect with unseen movement happening around and behind the immediate subject and is important in the narration of battle scenes (e.g. in Star Wars).

A good example is when watching the football match, they always follow the 180 Degree Rule because if they cross the 180 line, the viewers will get confused on which team scored.

BUT...

Like they say, all rules are made to be broken.

In professional productions, the applied 180-degree rule is an essential element for a style of film editing called continuity editing. However, the rule is not always obeyed. Sometimes a filmmaker will purposely break the line of action in order to create disorientation. Stanley Kubrick was known to do this, an example being the bathroom scene in The Shining.

In The Shining, Stanley Kubrick shoots wide shots from both directions, a 180 degree flip, crossing the line.

 In the first shot, Jack Torrance is standing on the left, with his back towards the camera.

In the next shot, Jack Torrance is all of a sudden standing on the right, but this time he is facing the camera.

Still not getting it? Watch this short clip!