The other day, a student asked me how many characters she should have in her novel. My answer was simple. Only as many as you need.
A character is in your story because s/he serves a purpose. S/he is the protagonist, the antagonist or part of the supporting cast. She might be the doctor who patches up the detective every time he gets beaten up, or he might be the bank teller who appears only once and has only one line. Whoever the character is, she must be someone you can’t do without, and if that person turns up frequently, consider making her serve two roles. For example, the doctor may also be the villain. That not only adds complexity to the character by showing both the good and the bad side of her, it can also add an unexpected twist to the story.
A cast of thousands might sound interesting, but I’ve read novels that have so many characters I can’t keep track of them. You have to consider the “exasperation level” of your reader.
The same rationale works for scenes. Whether your novel is literary or commercial, each scene should have at least one specific purpose—preferably more—and should forward the story. The pace may be slower in a literary novel but no story should stand still. Before you write a scene, it’s a good idea to consider what you’re trying to accomplish.
Suppose the purpose of your scene is to introduce the romantic lead. That’s fine but consider ways you can do more than that. A series of one-purpose scenes can make the plot feel slow. Perhaps the heroine meets him during a bank robbery that sets the whole story in motion. You’ve not only introduced a character that’s important to your story, you have put him and the protagonist into action. It’s even better if you can come up with a third reason for the scene. Perhaps he’s playing an active role in the crime or maybe the heroine is.
Like good characters, good scenes are complex units of conflict, drama and emotion, and as the plot goes along, the scenes should increase in intensity and tension toward a climax and a resolution.
Look at your own characters and scenes. Do they serve more than one purpose? Do the characters act in a way that’s important to the story? Do the scenes increase the tension as the novel progresses? If your answer is no, you probably need to do some rewriting.