And that's why these people (among many others) all say this: http://www.wow-womenonwriting.com/30-FE2-WritingFantasy.html "5. Bound by Rules. No matter what fantasy world you set up, no matter who your characters are, the rules you establish are the rules you must use from the opening page until the very end. The trickiest rules concern the magic in your world. Who can use it? When? Wands or spells or potions? Or all three? If your character must clearly speak an incantation to make a spell work, gagging that character will put a real damper on the magic. A character who needs sunlight to power their magic can’t suddenly perform by the light of a single candle just to save the maiden fair. Sometimes the character must struggle with the rules. In Harry Potter, junior wizards and witches are not allowed to perform magic in the Muggle world. Do it only at a steep price. In A Curse Dark as Gold, Charlotte realizes she has to break a curse, but to do it, she must figure out the rules of the magic that is so new to her. Learn to work within the rules of fantasy. Use these rules and the inspiration of so many subgenres to create a unique fantasy world that editors and readers alike will want to explore." http://www.watt-evans.com/lawsoffantasy.html Watt-Evans' Fifth Law of Fantasy: Magic, like everything else, has rules. http://fantasy.fictionfactor.com/articles/fantasyrules.html Begin with the world. Creating the world where your fantasy novel is set is one of the most important parts of creating a successful fantasy novel. And this world must be pretty fleshed out before you move on to the next step. Why you ask? Because just as earth has specific rules that cannot be violated without explanation (for example, the law of gravity), your world will have laws too. It will also have its own geography, weather patterns, animals, and races of people and/or other fantasy creatures. If you jump right in and begin writing your fantasy novel without any consideration for these rules, you will find yourself in a situation where you will need to rewrite carefully to avoid any contradictions once your world has been fully created.