In the 1920, Vladimir Propp was a Russian critic. He was mainly interested in narrative Folk tales as he believe that Folk tales were about the same basic struggles, therefore had the same characters. According with the Propp theory, characters have a narrative function as they provide a structure for the text.
Let’s examine how those roles function in most movies. Let’s start with the big ones.
The Protagonist (The Hero)
The protagonist of your story is the central character. The character that is referred to as “the hero,” whether they are actually doing something heroic or not. S/he is the character that the audience should most identify with. S/he is the one who should lead the audience on the journey through this story, whose choices should resonate and makes sense to the audience, even if their actions don’t.
For example, hopefully, we wouldn’t want to go out and kill someone; but if the hero of our movie is a hitman, we would want to agree with the hitman’s decision to go out and shoot someone. The protagonist is the character who drives the plot forward with his or her choices and decisions.
The Antagonist (The Villain)
The antagonist is the person who stands in the way of your hero. Usually, that is a person. On occasion, it can be a place or a thing.
In “2001: A Space Odyssey,” the antagonist was Hal the computer. In “Fitzcaraldo,” the antagonist was the mountain they were trying to get the boat over.
It can be an animal, an act of nature, a ghost or demon. It can even be within the main character’s own psyche. Regardless, of who or what it is, the antagonist must have a need as great or greater than that of the hero; and at the beginning of the story, the antagonist must appear more powerful than the hero.
Another essential quality for an antagonist is that compromise must not be a viable option. The antagonist must need to stop the hero from achieving his or her goal at all costs, or the antagonist will be perceived as weak and your story as boring.
In good scripts, the antagonist is as equally developed and multi-dimensional as the hero. This is what makes the conflict between the two main characters so interesting.
When creating a strong antagonist, the writer should look to make the antagonist as human and compelling as possible. The more understandable and acceptable the motives of the antagonist, the more the audience will understand the antagonist and the more difficult it will be for the hero to triumph
Supporting Role (The Sidekick)
Today, many movies are “buddy movies” of one kind or another. Even then, one character is more the protagonist than the other.
In “Lethal Weapon,” Martin Riggs, Mel Gibson’s character is the “hero.” But Roger Murtaugh, Danny Glover’s character, is the protagonist of the story. He’s the one who want to retire and be with the family; he’s the one who’s home is invaded and daughter taken; and he is the one who at the end is reunited with his family. Martin Riggs is the side-kick.
This brings up an important point about supporting characters. They must be developed and created into fully realized characters as much as the main characters. In fact, these characters should be made to be more quirky and interesting and clever as they will not be as constricted by the plot as your protagonist and antagonist.
Supporting characters are also the characters that deliver your theme. Through his or her actions, the protagonist projects a world view that the writer hopes will engage the audience cause them to root for that view to triumph. Through his or her actions, the antagonist presents an opposing world view that the writer wants the audience to see vanquished.
The supporting characters may or may not have plots of their own; and as such, they are free to reflect the themes of the story in their habits and behaviors and ways that they speak moreso than the main character. When they are involved in plots of their own, these characters will mirror the main story.
In “Casablanca,” the character Ferrari to whom Rick sells his café represents the corruption caused by the war, and he talks about it freely. The Chief of Police, Captain Renault, has a story involving a young bride willing to sleep with him for safe passage to America which mirrors the main story between Rick and Ilsa.
In almost every story, there is someone who helps the main character by teaching him or her something that s/he needs to know. The most easily understood is Obi-Wan-Kenobi in “Star Wars.” Han Solo is also a mentor; but Han is more of a supporting character. Obi-Wan is the one who teaches Luke Skywalker how to be a Jedi. In “St. Vincent,” the mentor is the boy that Bill Murray is supposed to care for. It’s the young boy who teaches Bill Murray how to love himself, which frees Murray’s character Vincent from the self-loathing that has entrapped him since his wife died.
The Love Interest (The Princess or The MacGuffin)
In love stories, someone wants someone else. Usually there’s another suitor as well who complicates the matter. In mysteries, there’s a riddle that needs to be solved. In action-adventures, there’s an object of great power and wealth that is desired.
Every story has it’s object of desire.
Sometimes that’s a romantic lover, sometimes something else. In most stories, this is what the main character hopes to earn through his or her actions. In romance stories, this is the main plot. In other movies, this is what motivates the hero.
In “Die Hard,” John McClane wants to vanquish the bad guys and save all the hostages in the building. Why is he doing this? Because he’s a cop, and it’s what he’s trained to do. But why is he really doing this? Why did he fly all the way across the country on Christmas Eve…? To be reunited with his wife, Holly, which is exactly what happens at the end of the movie.
In “Shampoo,” Warren Beatty’s character George Roundy wants to get the money to open his own shop, but what he really wants is to win back Julie Christy’s character Jackie whom he loves. Being a film from the 1970, writers Robert Towne and Warren Beatty upend the genre by not letting Warren Beatty win his love interest. In the end, Jackie’s rich boyfriend Lester gives George the money he needs; but Jackie goes off with Lester leaving George devastated at the top of Laurel Canyon.
Minor characters are the people who populate your story. They are the people with whom your protagonist and antagonist interact. They are helpers, random people, henchman, vigilantes, stoner roommates, mean girls, good girls, teachers, parents, etc.
While they may only exist in a single scene to fulfill a function specific to that moment, the less stereotypical and more interesting you make them, the stronger your script will be. You don’t want them to be so over the top that they pull the focus from your hero and story, but every person in a movie matters.