Most fantasy stories include magic in some form. As a writer of fantasy, you must consider various aspects of magic, such as who wields it, to what degree, and to what purpose. Also weigh at what cost to the user, especially if the user experiences weakness and needs time to recover in order to be back at full power.
In order to be believable, magic must be consistent. For example, if the wielder can quell fire, why doesn’t he when the cabin in which he is sheltering is set on fire by an enemy? If magic is unpredictable, that might be fodder for an unusual story, but will readers buy into it?
A good way to keep track of the ways in which magic plays into the drama is by keeping notes and checking them frequently. Record the person, power, cost and use. As characters’’ powers change, remember to return to your chart and list them as well.
Another factor is public attitude toward magic in your world. Is it revered or feared? Is it a common trait or rare? Is it honed through learning and practice or wild and uncontrollable?
Your task is to create a list that documents who has magic, what type and how it is used. Once this is complete, write a story in which magic influences the outcome, either positively or negatively.
Don’t overdo it. A little magic can be more powerful than a devastating wizards’ dual.
Have fun with this one.