Worlds Need Rules

I like writing. No, not just my weekly essay (which is certainly not a rant), but fiction. Sometimes I write stuff grounded firmly in this world, but I really enjoy building worlds of fantasy or science fiction. I’ve got a science fiction side project I like to fiddle with here and there and I run a fantasy RPG with some friends. For both of these I’ve made intricate worlds with some semblance of a history and culture. But just as important as the setting of a story is the exact nature of the world. Any ‘magical’ force, be it mystical or scientific, needs rules to go with it.

Mass Effect is set several centuries in the future, after humanity has made contact with not only the technology of an ancient race that came before but with the various alien species that populate the world today. How does this work? The titular mass effect fields that can increase or decrease the mass of a volume of space time. This technology allows usual science fiction tropes like shields, faster-than-light travel, and artificial gravity; or provides mundane justifications like how buildings can be so tall or preventing spaceships from being hit by space debris.

What makes this so wonderful isn’t just the encyclopedia’s worth of pseudo-science, it’s that everything within the universe adheres to this rules. Because of this we can’t have, say, a ship the size of the Normandy obliterating a planet. No matter how much you’d want to chalk it up to a mass effect field, the rules of the universe prevent it. The writers have their rules to limit the extent of their technology in the world. So long as they don’t supersede these rules, the universe works.

Harry Potter is about magic. Simple. You say a spell (or do it silently if you’re good enough) and magic happens. Feeling lazy? Accio remote!* Someone’s making you really mad? Avada Kadavra. Of course, that means you really do mean it and have created a very permanent solution to what was probably a very minor problem, you overreacting overreactor. But want to make yourself immortal, or make someone love you? No can do. That’s the rules of the universe.

Prior to writing the books, J.K. Rowling spent years detailing exactly how magic would work in her world. She had to set limits and rules on just how it worked. Something couldn’t come from nothing, for example. The world still has to function, magic or not.

The ‘physics’ of bending are established fairly early in Avatar: The Last Airbender. Like how benders need the element to control it (except for firebenders who channel their own chi into fire). That’s the main rule and anything that the characters do follows that paradigm. Were Katara to suddenly conjure up a burst of water in a desert our suspension of disbelief would be broken. Not because she can control water, but because the show broke their own rules.

We like to get lost in other worlds. But we need these worlds to be believable. This doesn’t mean whatever phlebotinum or plot device you have must be ‘realistic’ or particularly grounded in reality, it means that if you say something is a certain way, than that is the way it must be. We, the audience, will willing suspend our disbelief so long as the fantastical element remains internally consistent. Call it Aristotle’s Law Of Identity or Magic A is magic A, it’s the foundation of a believable world.

And if we can’t believe it then we won’t be invested.