The 180° rule is a principle of film making that allows the viewer to better understand spatial relationships between characters and their surroundings. Obviously, there are very few proper ‘rules’ in film making, and as such the 180° rule is more of a basic guideline.
Here’s a (hopefully) simple explanation: A line (imaginary, of course) connects characters, and by keeping the camera on one side of that line throughout the scene, the viewer will better understand the characters’ spatial relationships, even if they don’t always appear on screen or we don’t see a wide shot of the scene. It is probably most helpful during conversations between two characters; it will keep one person talking from what appears the left side of the room and the other from the right.
If this rule is not adhered to and the camera doesn’t stay on one side of the line, it is known as jumping or crossing the line. Using the conversation example again, jumping the line would result in both characters appearing to be talking from the same side rather than looking at each other. Here’s a delightful little diagram to illustrate the idea…
The 180° rule is essential for a style of editing called continuity editing, making a smooth series of events from what is essentially a collection of separate shots. However, it is not uncommon for directors to jump the line, and there are various reasons why they might do this. They might jump the line to create a sense of disorientation and confusion in the audience, perhaps in a dream sequence or to show someone going insane. It could also simply be a purposeful disregard for standard cinematic practice, such as during Jean-Luc Godard’s French New Wave classic À bout de souffle.
Another possible use is to show an integral link between two characters, suggesting that as they appear to be talking to and from both sides of a room, that they are similar or the same. This would support the jumping the line in the bathroom scene in The Shining with Jack Torrence and Delbert Grady, and also during Batman’s interrogation of The Joker in The Dark Knight. However, one of the most obvious examples is during The Lord of the Rings: The Two Towers where Gollum shows his dual personality by talking to ‘himself’. This example is essentially done by jumping the line, giving the impression that there are actually two Gollums. Watch the video below for a little reminder…
Of course, a director may have myriad reasons for jumping the line, and it is only really a ‘rule’ in certain circumstances. It helps to create the shot reverses shot of a conversation but it’s probably not necessary in situations such as people sitting in a car as it’s abundantly clear the spatial relationships between the characters and their surroundings.
For more entries in the ‘What is…?’ series, click here and (hopefully) learn a little bit about deep focus, chiaroscuro, German Expressionism, and more.