The Three Principles of Continuity

http://uk.youtube.com/watch?v=QehZjjwb7-I

The first rule of continuity is shot-reverse shot. This is used at the very beginning of the scene, when the Joker walks into the room. We first see a shot of the Joker's back, tracking him as he walks into the room, then, at 12 seconds, the camera angle changes and we see the Joker's face.

The second rule of continuity is the 180 degree rule. This is used when the characters around the table are in conversation. For example, when one of the people is talking, we always see them from the same angle. The same goes for the Joker, whenever we see him when he talks, it is always from the same angle.

The third and final rule of continuity is match on action. We see this when one of the characters gets up at the 24th second and the shot cuts to see him walking around and getting hit onto the pencil by the Joker.