Vladimir Propp's theory.

Vladimir Propp's theory of narrative.

According to Propp, characters serve as a narrative action. Providing structure to a play, book, film, etc.
Nearly all narrative's follow the same 8 characters.

The Hero- The protagonist that has a goal to accomplish. E.G Rocky's goal to win the match in Rocky.

The Villain- The main opposition to the hero, obstructing them from their goal as much as possible. E.G The Government in the Hunger games, opposing Katniss' goal to survive.

The Donor- A helper to the protagonist of sorts who provides them with some sort of useful item or information, vital to their goal. E.G Grace providing Jake with his Avatar.

The Dispatcher- The one who gives the hero their goal/quest. E.G Gandalf telling Frodo to destroy the One Ring.

The False Hero- This one is less common but they disrupt the hero's progress by making fake claims. E.G J. Jonah Jameson Jr., the reporter from Spider-Man constantly out to slander him.

The Helper- The number one ally of the hero who aids them in their goal. Their are usually multiple helpers but traditionally, one is more prominent in the plot than the others. E.G Baymax in Big Hero 6.

The Princess- The reward for the hero. Not always a person but usually the "damsel in distress" that the protagonist acquires when he gets the girl. E.G Elsa when Anna ventures out to get her sister back in Frozen.

The Father- The one who gives the reward to the hero for completing their quest. E.G the King in Shrek 2, Fiona's father.