The 180° rule is a guideline used in film making. The rule considers the spatial relationship between characters and objects in a scene. The practise uses an imaginary line called an axis or line of action. The axis is a straight line that is between a person and the item or person they are interacting with or simply a line to mark a path that a person is moving along. It is a guideline within itself as it defines where the camera can film from. The camera is on one side of the axis and remains on that side otherwise the characters switch places on the screen. By keeping the camera on a particular 180° section, semi-circle, the first character is always frame right of the second character and vice versa. If the camera switches onto the other half then the direction faced by the characters will be different along with their sight lines or will show a character carrying out an action, for example walking, in the wrong direction. The 180° rule is important as it allows the scene to become more realistic and makes it easier for the viewer to watch as the scene flows much more easily. It also allows the footage to be more interesting with varying shots without breaking the continuity.