The 12 Principles of Animation

(From The Illusion of Life)
1.  Squash and Stretch: One of the most important discoveries that the original Disney animators made was the concept of squash and stretch.  In early animation, there was a “marked rigidity” as the characters moved around and did actions that are not similar to the dynamic movements of real life.  By squashing and stretching characters, they were seemingly injected with new personality and life. 
2. Anticipation: The audience must be prepared for the next sequence of actions on the screen because they will not be able to understand why or how it happened if they were not expecting it.  This allows the audience to connect more with the characters as well as catch more subtleties.
3. Staging: Staging is a term that has been used for a very long time in the theater and has a broad meaning.  In animation it is the “presentation of any idea so that it is completely and unmistakably clear.” (p. 53)  Staging answers the questions of whether the shot should be close up, far away, from what angle, etc.
4. Straight Ahead Action and Pose to Pose: These are two different, yet equally viable, approaches to animation.  Straight Ahead Action is when an animator just draws a scene, drawing actions as they happen in a very spontaneous fashion.  Pose to pose is a more planned out approach where the animator will pick the key frames and draw those leaving the in-between frames to be done by an assistant.
5.  Follow Through and Overlapping Action.  This step came about when animators began to tackle the problem of characters coming to sudden and complete stops after they finish an action.  Walt Disney knew that “things dont come to a stop all at once…first there’s one part and then another.” (p. 59) This allowed for more realistic movement for characters as well as added gags for comedy (a jiggling tummy or floppy cheeks).
6. Slow In and Slow Out: Basically, this term means that the key frames were approached slowly leading up to them and leading out of them.  The in-betweens on each side of the key frames would slow the action creating a very sincere effect with characters changing attitudes and actions very quickly, but still allowing the audience to see the important frames.
7. Arcs: Compared to earlier animators who drew characters following rather linear paths, DIsney animators noticed that objects tend to follow more of an arc.  This added more bounce and movement to Disney drawings.
8. Secondary Action: Secondary actions are those actions that give support to the primary action of a scene.  For example, “a flustered person puts on his glasses as he regains his composure” or “someone stunned shakes his head as he gets to his feet.” (p. 64) Animators have to be careful to pick the right secondary actions and not let them overcome or contradict the primary action. 
9. Timing:  This has to do with the number of frames that will be given per action.  The more frames, the longer the action takes, so depending on how immediate the action is determines how many frames will be used. 
10. Exaggeration: This was how Walt Disney got to the heart of characters and emotions.  He believed that the broader the action, the more exaggerated the facial expression, the more believable the animation was. 
11. Solid Drawing:  It is important to have solid drawing skills before attempting animation because animators have to understand the basic movements and subtleties before they can draw great cartoons.
12. Appeal:  This is simply that if a animation lacks appeal, then it isn’t good.  The audience has to be able to connect with the animation, not meaning that they have to love it, but rather that they have to feel for it.  Disney animation had great appeal and still does which is why they have lasted so long.