Mechanics of the Unexplained

Theory

I've spent enough time with city ordinances to know that a rule without a reason is just a whim. In this archive, we talk a lot about lore dumps, but the opposite problem is just as bad. Some writers think that keeping a supernatural element completely vague is the only way to maintain tension. They call it the power of the unknown. From where I sit, that often looks like a shortcut for lazy worldbuilding. There is a massive difference between a secret and a hole. If the rules of a haunting or a monster shift whenever the plot gets stuck, the reader stops caring because there is no internal logic to lean on. On the other hand, a full technical manual for a demon kills the mood; it turns a nightmare into a plumbing problem. You need a baseline for the stakes to matter, but you cannot over-explain the machinery. Where is the line between a necessary mystery and a lack of preparation? Give an example of a void that actually worked or a mechanism that ruined the tension.