The Causal Chain And Why Your Story Needs It
The most obnoxious thing my writing teacher taught me every story needed, that I absolutely loathed studying in the moment and that only later, after months of resisting and fighting realized she was right, was something called the causal chain.
Simply put, the causal chain is the linked cause-and-effect that must logically connect every event, reaction, and beat that takes place in your story to the ones before and after.
The Causal Chain is exhausting to go through. It is infuriating when someone points out that an event or a character beat comes out of nowhere, unmoored from events around it.
It is profoundly necessary to learn and include because a cause-and-effect chain is what allows readers to follow your story logically which means they can start anticipating what happens next, which is what is required for a writer to be able to build suspense and cognitively engage the audience, to surprise them, and to not infuriate them with random coincidences that hurt or help the characters in order to clumsily advance the author's goals.
By all means, write your story as you want to write it in the first draft, and don't worry about this principle too much. This is an editing tool, not a first draft tool. But one of the first things you should do when retroactively begin preparing your story to be read by others is going step by step through each event and confirming that a previous event leads to it and that subsequent events are impacted by it on the page.
When your character is standing knee-deep in literal or metaphorical shit with a weapon in one hand and their last hope of surviving evaporating around them, and they’re wondering how their simple smuggling job/adulthood ritual/simple morning in an ordinary village led to ALL OF THIS, both they and the reader need to be able to backtrack through every single choice, mishap, attempt at fixing earlier problems and panicky flight or fib led them unerringly to this moment. That chain cannot have breaks in it, or you lose the whole impact.