Like how I title this as though I know anything about it? I don't, but I am going to summarize what I believe to be the most important elements of developing dynamic characters.
(I've decided one approach to this blog will be to discuss the various elements and issues of writing stories in general, at least until I get to the 'figuring out how to get this thing published' part. And this will be beneficial to me to talk myself through even if I never have any "followers" to help me out.)
I think the two most basic elements of a story are character and plot, and since I think plot comes out of character 95% of the time, it makes sense to start with character.
It is important to know everything you can about your character, including an assortment of details that might never be mentioned in the actual narrative. You should know what your character is likely to have in his or her pocket, even if being aware of that stick of Juicy Fruit is entirely irrelevant to the story you are trying to tell. You should know more about your characters than the readers could ever know. I think, regardless of what POV you are writing in, it is good to know how your character would sound in the first person. Maybe pick an important scene in your story, in which multiple characters are involved, and write that scene from the perspective of each character. See what differences emerge.
Another important element is giving a certain amount of freedom to your characters. They might not always want to do what you want them to do. Your characters will surprise you as you go. In a sense, they really do take on a life of their own. Let's say you, as I have before, have a very clear idea of what you want to happen in your story. And you know exactly what each character must do to achieve the desired ending. So you are writing along and you find yourself having a hard time getting a character to behave accordingly. You just can't find the right thing for them to say or do, nothing feels right. But you need them to do this thing. Well, if it doesn't come naturally, than it probably isn't something your character would realistically do. And you can force it, sure, but it isn't going to work well. Readers might even notice, might comment that it seemed odd, or even out-of-character, for so-and-so to do or say such-and-such. And if readers feel like a character was out-of-character, you must have really messed up. After all, as I said in above, you should know your characters better than they do. And that means you need to know when to be flexible and let your characters do what they will.
I realize this might sound strange to people who haven't ever really tried to right a story before. Many people think the writer has all the control. But that just isn't the case. You create these characters, but then they grow up and they make their own decisions. It's really probably something like raising children-- believe me, you can lose sleep over them, be angry with them, disappointed in them, surpised by them, proud of them... There are a number of things in my current story that have changed since I began. Most changes are the result of characters behaving differently than I'd originally anticipated.
People behave differently when they are around different people. I've encountered a number of amatuer narratives in which a given character seemed to act the same way no matter who they were interacting with. This brings me to a third issue: don't think it's out-of-character for a character to act one way with one person and another with someone else. Every relationship should be different. Some might be similar, sure, but there are always differences, however small, and they are important to understanding the way the relationship works. And, obviously, understanding the way the different relationships work helps to understand the individual characters involved as well. Who are they close to? Who do they trust? Who are they defensive around? Who do they like? Dislike? Who they trust, but hate, and are defensive around? Who do they love, but not trust, and not like, and not feel remotely close to? Do they really even love that person? Who makes them feel safe and secure? Who thrills them? Who hates them? Who loves them?
If you have two characters that are exceedingly similar, which you might not realize until you are a ways into your story, but which close attention to the nuances of behavior in their relationships with each other and other characters will reveal, then you should probably make them into one character. No use in cluttering up the narrative unless there is a purpose in their similarities or if you are intending to have them go very different ways by the end.
Sometimes characters can be fun and different from your others, but can end up not really serving a particular purpose, not advancing the story at all. These characters are probably best to cut as well, although you should probably keep them in mind as an idea might come up along the way and you might find a path for them. I would keep them around in the first draft, just to see if they find their way. If they don't, they get cut when I go through for draft two.
Off the top of my head, those are the important things to remember.
To sum up:
1) Know everything you can know about your character (even though it won't be everything and they will surprise you).
2) Do not have them on a tight leash and do not force them to do things they don't want to do.
3) Give the various relationships between all characters due attention and detail.
4) Cut unnecessary characters or combine them. (Keep them around in draft one, just in case, but be ready to cut them in draft two if they don't advance the story).
Coming Up Next: Plot, maybe. Maybe not. We will see what mood I'm in.