180 Degree Rule

180 Degree Rule - In filmmaking, the 180-degree rule is a basic guideline regarding the on-screen spatial relationship between a character and another character or object within a scene. An imaginary line called the axis connects the characters and by keeping the camera on one side of this axis for every shot in the scene, the first character will always be frame right of the second character, who is then always frame left of the first. If the camera passes over the axis, it is called crossing the line or jumping the line.

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