Characters are vital to the storytelling process. They're how we relate to and tell the story. Without them, a good story rarely exists (if you'd like an example of a character-free story done well, check out Tesseracts Nine: New Canadian Speculative Fiction, edited by Nalo Hopkinson and Geoff Ryman, specifically their “Against Character” chapter. We read this in my Speculative Fiction class and I highly recommend it if you're considering writing Spec Fic.).
Writing believable characters can be achieved many ways.
Ask questions. You might want a character sheet for this route (they're easy to find through an internet search). Start with the basics – full name, meaning, any nicknames, and the reason they exist in your story.
Physical appearance can help the reader visualize the character, which brings the story to life. Things like age, how old they look, eye and hair colour, height, skin tone, face shape, fashion sense, accessories, the basics. Avoid things like food references for skin colour – no one wants to read about another chocolate-, mocha-, or cream-skinned character. Be creative when describing physical attributes: eyes like a deep blue lake – old and overdone; eyes as dark as the black hole at the centre of the Milky Way – new.
A quality character has depth: a background. Characters without history are flat and boring; people will stop reading and that's not what you want! Add things like hometown, childhood, first memory, favourite memory, habits, hobbies, and the person they consider most important to provide layers to the character and make them more life-like. Also consider: what they do too much of, most prized possession, education level (this will help you create more life-like dialogue too), are they religious, financial situation, and relationship with family.
Problems drive story narrative, so how does the character react in a crisis? Why? What kind of problems will the character survive throughout the story and how do they deal with them? What about their personality indicates how they will react? Are they good with change?
Check out this handy character checklist I found at Pub(lishing) Crawl.
Another way to make dynamic characters is create five secrets for the character. These secrets will never appear in their entirety in the story but they might bleed into how the character reacts or behaves. Maybe your character hates petunias, has a medical condition they don’t share, is afraid of fading away into nothing; the possibilities are endless.
It's important to note this method of dynamic character creation should be used as a supplement to another method or to add depth to a character that alpha or beta readers have pegged as "flat".
Astrology also adds depth to character creation as there are many aspects that can affect behavior. Sun signs, moon signs, rising sign; figure out when your character is born and you will have a ready-made list of traits at your fingertips. Use your favorite internet search for the character's zodiac sign and make them typical… or opposite! Numerology adds even more layers to personality through birthday number, life path number, inner dreams number, and more.
Using myself as an example, I am a Cancer with a life path number of 7, a birthday number of 5, and an inner dream number of 7. The Cancer sign is said to be emotional, loving, intuitive, imaginative, sympathetic, changeable, and moody. Life path of 7 suggests a thinker, peaceful, enjoy solitude, intellectual, scientific, studious, pessimistic, and lackadaisical. The birthday number reveals I work well with others, I am versatile, progressive, imaginative, a bit impatient, with a tendency to shirk responsibility. And finally the inner dream number suggests that I dream of having the opportunity to read, study, and shut myself off, and that I will spend my life in the pursuit of knowledge.
Remember there are negative character traits too. Your character should not be perfect; perfect is boring. The perfect person does not exist, so the perfect character shouldn’t either. The best and easiest way I've found to determine whether a character is flat is the Mary Sue/Gary Stu test. This test is a series of questions about the character. How you answer these questions determines the character's score on the Mary Sue/Gary Stu scale. If a character scores too high, they are considered a Mary Sue/Gary Stu and fail the test. Mary Sue/Gary Stu is a term that simply means “idealized and seemingly perfect fictional character”. You can find an array of Mary Sue/Gary Stu tests available through an internet search.
There are many other tools to help you create dynamic characters: the Myers-Briggs scale, Keirsey Temperament Sorter, random character generator, Sims (a personal favourite), etc. No matter which method(s) you choose, make sure that the characters are well-rounded and realistic. Let them have flaws and make mistakes. Sometimes the protagonist screws up. Sometimes they do everything right and still lose. Make sure your characters reflect their personal struggles and they will be dynamic.
About the author: Robyn Cross holds a BA in Creative Writing from Vancouver Island University. You can find her on twitter: @poorwritergirl.