Types of CharactersThere are many types of characters in a story. We can break down these characters into two artificially simple categories: major characters and secondary characters. We could call them functional characters and artistic characters, or superficial characters and deep characters. The only real separation between them is how we use these characters in the story.
Secondary CharactersSecondary characters are primarily functional characters. They serve an identifiable purpose in the story. We could also call them superficial characters because they do not have an inner life to display. These secondary characters can be as simple as an usher, the protagonist’s idea-prone mother, or the family dog.
Secondary characters give your story all sorts of things while demanding nothing. They are there for your major characters to function against. They work best when they are underdeveloped.
The human mechanism behind secondary characters is very interesting. In our everyday lives, we meet many people with whom we are not familiar with, yet we must interact with them in some predictable manner, so rather than interact with them according to their personality, you interact with them according to their roles. For example, one person is a customer and the other is a shopkeeper. Both sides of that interaction assume predictable roles. This artificial shallowing greatly facilitates the business of buying and selling.
Because the roles provide so much weight to the character, it only takes a few words to make a secondary character seem more real than she really is. Just by being a florist, the role gives that secondary character predictability and purpose. The reader instantly brings all their own expectations of “florist” to the character, thereby loading out the character. Tack on one or two descriptions, such as “new age crank”, and the character seems far more real.
Major CharactersIf there’s any simple touchstone to identify a major character, it’s that major characters require many cheap tricks to make our audience believe in them. Because our readers spend so much time with these characters, readers look upon our major characters as other human beings, which means that our readers bring their massive human brains to bear on the characters. If there are problems with our major characters, our readers will find them.
Major characters have three traits that should be met. They must be consistent, persistent, and predictable.
By consistent, I mean that most facts and traits belonging to the character should remain consistent throughout the work. Most characters won’t have changing back stories, shifting personalities, and wildly changing social situations. During the stories any or all of these may alter, but such alterations must make sense in context of the story. Given any lack of overt change, nothing should change.
By persistent, I mean that throughout the changing tensions of a story, a character’s unique personality keeps asserting itself. If necessary, the character may step back from his personality sometimes, but sooner rather than later, will his own personality come back to the forefront.
By predictable, I mean that your audience should be able to reasonably predict the general actions of your character into some ordinary future. When characters deviate, and they do deviate, the deviations should make situational sense to the reader.
If you fail at upholding any of the above traits, then your audience gets annoyed.
Cut CharactersStrategically leaving characters out is a smart idea in many genres. If a character imposes too many logical problems in your story, then cutting the character, never mentioning them, and ignoring the logical hole you created often works wonders. Don’t worry about your readers noticing. Most of the time, they will be so busy that they won’t notice. Some will, of course, but a reader will always find something that doesn't quite jibe, so don’t worry too much about it.
In many adventure books, the hero is a bachelor with no noteworthy family connections. If there is family, they are different. The author efficiently removes any such characters from the work where logically such characters would normally exist. In fact, in any person's life, there are so many people that covering them in a work of fiction becomes unwieldy and unsustainable, so you just put in a few friends and family.