Rules are the 'way of things' in the worlds where stories take place. They can influence the who, what, where, when, why, and how of a scene. For instance, if a scene in your story takes place in Virginia in 2011, your reader is likely to assume the characters have access to computers and cell phones with cameras. However, in 1988, people didn't have smart phones with digital cameras and computers weren't the staple they seem to be now. Okay, this is a simple example and basically common sense. Let's take it up another notch.
Let's suspend reality for a moment and say you are in Virginia in 2011 and there are such things as vampires, werewolves, fairies, and/or wizards. Now, the real Virginia of 2011 no longer exists, but to what extent? Think about the Harry Potter books and the Twilight series. In Harry Potter's world, many of the magically beings live separate from the muggles and didn't understand the technology they use. In the Twilight Saga, the vampires and werewolves were fully integrated into the people of Forks and they do use the technology. However, in both series, the fantasy beings are a secret.
What rules will you define (or ignore) in order for your characters to integrate into the world we know? For instance, how is it possible for witches and wizards to live within a technology-based society and not have some idea how things work? I can't answer that, but J.K. Rowling found a way to make it work. By placing the majority of the scenes at Hogwarts or other magical places unknown to muggles, she took the reader away from cars, cell phones, etc. In the Twilight series, the main characters were fully integrated into the world we know. They went to school with each mortals, they worked with mortals, and they used the same tools as mortals ( cars, cell phones, etc.). Of course, you could simply rewrite reality as Laurell K Hamilton did in her Merry Gentry series, where fairies live in the United States with permission granted by a treaty they signed with the government, and everyone knows of their existence.
The idea of integrating fantasy characters into reality brings up another aspect of rules. If you are using fantasy beings that have been defined by authors who have come before you, will your fantasy beings follow the same rules? The Twilight vampires and werewolves break all the rules. The vampires can go out in sunlight and not die. The werewolves are actually shape shifters, of a sort, and not influenced by the moon, but instead, the presence of vampires. Stephenie Meyer suspended many pre-existing rules and introduced a new set. In Harry Potter, there doesn't seem to be a price for the use of magic. I guess that's why it's magic.
But what if your story doesn't take place in the world in which we live? What if it takes place in Middle Earth or some other world? What then? Will your other world be high tech, leaning more towards science fiction? Or will your world go in the opposite direction and reflect a time where technology (the kind we know) didn't exist-common practice in fantasy stories?
If you are going to define your own fantasy world, what kind of world will it be? For instance, will your world have modern conveniences such as telephones or something else? Let's explore a basic concept, long distance communication. If your world will need it, how will it happen? Will they have magical crystals that project a hologram in real time? Or will they use people or animals to deliver messages. Each of these methods requires a set of rules.
Communication by magical crystal hologram rules:
- Where does the power come from: the person holding the crystal or someplace else? Will the source of the magic ever run out?
- How far can a crystal project? Around the world or maybe it's limited to a few miles, thus adding barriers your characters must overcome.
Communication by human or animal delivery rules:
- Is the message written? Is yes, how big is it? Depending on who/what is carrying it, the size of the written message matters.
- What distance must be traveled in order to deliver the message? Are there any barriers such as water or mountains that must be traversed to deliver the message?
Above are only two examples of one concept. These questions only scratch the surface. For example, if your characters rely on snail mail to deliver a message, what will your characters do while they wait? Or what will your reader experience while your characters wait? Will you jump a head a day or two in the next chapter and just avoid that block of time or will you switch to another story thread that is happening and bring your readers up to date with that other set of characters?
When I wrote The Gifted, I started out with basic rules and then shaped them as I went along. I'd love to share the challenges I faced when deciding how to make a scene move forward when my own rules prevented it, but that would spoil the stories. My advice, keep a journal with every rule you define and why. Refer to it regularly, updated each time you tweak or refine a rule. That way you don't do what I almost did and grant one of your characters the power of another.