You can think of your cast of characters as planets in orbit around the sun – the sun being the inner poetic truth of your story. As the planets circle the sun, their gravity fields tug at each other’s orbits. Each planet affects, and is affected by, every other. They revolve in such perfect balance that if one is removed, or if an extraneous one is introduced, the whole system crashes.

A good story works the same way. In other words, all the characters exist in relationship with each other, and each character is necessary to the balance.

So you can see that randomly adding a new character is not a simple matter of fleshing out his personality and physical details. Each new character changes everything. That’s why assembling your cast of characters is an art.

Juggling a large cast is a challenge even for very experienced writers. At the most basic level, readers find it hard to remember a lot of different names. They may have to turn back through the pages to figure out who’s who. This can spell disaster for your story.

Your goal is to make your entire cast of characters come alive in your reader’s mind so that your story flows smoothly and naturally to its dramatic conclusion. This is not easy, but here’s what my writing journey has taught me so far:

Minimize the number of characters. In your first few stories, limit yourself to just two or maybe three characters, but concentrate on portraying each of them fully and developing their relationship well.  As you gain experience, you’ll see what it takes to keep your cast in balance. Then you can challenge yourself to work with larger casts.

Stick with one protagonist. This is the person at the center of the story, the person with whom your reader identifies. Usually, you will tell the story from this person’s point of view. Two or more protagonists are very difficult to keep in balance, so wait till you gain experience before trying that kind of story.

Stick with one antagonist. This person opposes your main character and sets up the conflict in the surface plot. Even if the real conflict is internal – within the heart of your protagonist – you can echo it metaphorically with an external antagonist. Some stories include many antagonists, but this requires an expert touch. If not well handled, multiple antagonists will dilute and weaken the conflict.

Make each character’s role distinct. As you plan your cast, be sure each character plays an essential role that’s different from all the others. Beware of “twinning.”  For example, say your main character has two friends in whom he confides. Or say he has to deal with two stone-walling bureaucrats. If you have two characters who basically perform the same function, ask yourself if you can collapse them into one. This can give your story a cleaner, sharper focus.

Make each character’s appearance distinct. In a crowd of faces, the ones you remember are the ones that contrast most in appearance. In a story, too, contrast helps your reader see each character better. So differentiate each character with a unique appearance, speech patterns and body language. And as always, choose these contrasting details to reveal something important about his personality.

Make secondary characters earn their roles. Name and flesh out your secondary characters only when they are essential to the story. If a character is simply performing a plot function that doesn’t affect the relationship among your cast, then keep him anonymous. For example, if you need someone to carry your protagonist’s bag, simply call him the porter and move on. Don’t give the reader unnecessary details that distract from the real story.

Limit the use of names. Naming a character  sends a signal to your reader that he will be important in the story, so give names only to key players. In scenes with minor characters, use “handles” like: the doctor, the tall man, the loud mouth. That way, the reader won’t feel obligated to keep track of names that really aren’t important.

Choose memorable names. Unusual names that are short and easy to pronounce are the easiest for your reader to remember, so be creative with names. Avoid using first or last names that start with the same letter:  Pete, Paul, Pat. Likewise, avoid names with similar endings:  Cindy, Judy, Suzy. You see how your reader might get them mixed up. Make all names start with different letters and end with different sounds. Examples:  Juan, Leda, Cass.

Use memory flags. Some essential secondary characters may not appear “on stage” for long periods in your story, so your reader will need a little help remembering who they are. When you first introduce this type of character, bring him to life with a few vivid details, and give him one memorable “flag.”  This could be a physical feature, a mannerism, a speech pattern, even a smell – whatever fits best. Then use some version of this “flag” each time he reappears to remind the reader who he is. For instance, a waxed mustache, a floral perfume, a stutter, etc.

Another option is simply to restate the character’s role in the story:  Anna, the travel agent. Jones, the cook.

In visual art, a successful composition is an evocative arrangement of contrasting shapes, colors, textures, lights and darks.  Everything is in balance. Nothing is extraneous. All the various elements combine to form one artful whole. So it is with the cast of characters in a story.