Propp's Theory

In Propp's theory, he examined hundreds of folk tales and concluded that a formula was commonplace, including:

8 character roles or spheres of action (character and action being inseperable)

31 functions, always highly predictable such as villain being punished at end of story

Character Roles

The villain - represents evil and struggles against the hero (e.g. the Salron in The Lord of the Rings)

The dispatcher - character who makes the problem in the narrative known and sends the hero on his way (e.g. Gandalf in The Lord of the Rings)  

The helper - helps the hero in his quest (e.g. Samwise in The Lord of the Rings)

The princess/heroine - the hero deserves her throughout the story but is unable to marry her because of an unfair evil, usually because of the villain. The hero's journey is often ended when he marries the princess, thereby beating the villain (e.g. Rachel in The Dark Knight) 

Her father - often rewards the hero with the princess/heroine (e.g. The Sultan in Aladdin) 

The donor - prepares the hero or gives the hero some magical object to help him in his quest (e.g. Lucius Fox in The Dark Knight) 

The hero - the centrail protagonist who leads the way in the narrative (e.g. Bruce Wayne/Batman in The Dark Knight)  

False hero - takes credit for the hero’s actions, is usually good looking and is often actually a coward (e.g. Harvey Dent in The Dark Knight)