180 Degree Rule

 

The 180-degree rule states that two characters in a scene should always have the same left/right side to each other. If the 180-degree is broken it can disrupt the scene and disorients the audience, If you break the 180-degree line, rarely is this rule broken.  

Chart of the 180-degree rule:

To understand this concept you must imagine a line going down the center of two people, when shooting using the 180-degree rule you must choose a side either the left or right of the character. Once the line has been chosen you should only film on that side of the character as this gives the viewpoint of two characters. If this line is crossed then you can risk disorientating your audience as the character's positions would be viewed as switched. In other words, if the 180-degree rule is broken then a person who was originally facing left in the scene can all of a sudden face right if the rule is broken. When thinking about the 180-degree rule a critical thing to imagine is a line going between the two characters, the camera can move anywhere along that line as long as it does not cross over it to the other side of that line.

Very rarely is the 180-degree rule broken a famous example of this would be : 

Joker scene 

In this Joker, Batman (Dark Knight) scene the 180-degree rule is broken, this is done presumably to show the change in power between the two characters, this is because we flip between different over the shoulder shots of the two characters. This is a very clever scene as it does not lose the audience however it makes the viewer feel dizzy as the camera spins around these two characters. I personally like this scene as it has a tense feeling due to the continuous breaking of the 180-degree rule. 

Example of the 180- degree rule: 

In this clip the 180-degree rule is followed, the camera stays on one side of the two characters without crossing the line. A clear eye line is kept between the two characters throughout this whole clip this allows for a direct line to be visible between the two characters further displaying that the camera is staying on one side of that line.