Any fiction book relies on suspension of disbelief by the reader. They forgo belief in some aspect of the real world to believe in the story-world. Science fiction and fantasy stretch belief to the limits requiring genre authors to exert great care to avoid “breaking the spell”.
At some point in a story this happens:
The doorbell rings, and John opens the door. Standing on the porch is a three-foot-tall, green creature with big eyes and fingers ending in suction cups. John says, “You must be the Martian. Come in before anyone sees you.”
As a reader, do you believe this is possible in the real world, is it logical, and is it expected? NO. That’s the wrong answer for a reader; they need to answer YES so they don’t hit delete or throw the book in the garbage. What is missing? The explanation.
Law of the Protected Premise
An author can immunize the reader against disbelief simply by offering a good explanation of a situation BEFORE IT HAPPENS. If the reader is told Martians exist and the Air Force has one at Area-51, then later when the protagonist meets a Martian: no problem. The premise of Martians is thus “protected”.
Rules to Generate and Maintain Belief
- Explain violations of actual reality before the reader encounters them.
- Explanations only need one level of complexity, e.g. the reason the crew of the Enterprise didn’t float around inside the ship is because of “artificial gravity”. Duh, of course, now we believe.
- Be internally consistent. Once a rule of the story-world is explained don’t change it.
- Be externally consistent. Outside of the explained rules of the story-world the rules of the real-world apply. Emotions, language, life, death and physical laws still apply.
- Very unlikely happenings, not fully explained, should occur very early in the story (so they can be quickly explained).
- All rules of the story-world should be elucidated (or foreshadowed) by the middle point in the story (middle of act two).
- Do not reference real-world events in the story-world, like a real movie or TV show because the effect is to remove the reader from the story, and it’s hard to bring them back.
- Avoid “plot holes” or illogical events that violate the rules explained for the story-world.
- A series of books continuing the same story poses a difficult problem. If readers wait months or years to read another volume they might not remember the rules of the story-world. An abbreviated reminder of the rules with a tiny bit of backstory is often needed.