Before you sit down to write your masterpiece of a fiction novel, you need to understand how to get from point A to point Z (from the beginning to the end). You have characters in mind and a basic theme/plot line. You know where you want to start the story and how it will end. Although I hate to burst your bubble, from my experience, it is never that simple and my ending never ends up being what I first thought. But that’s another item to discuss at a later date.
What I want to discuss this time is the basic structure for your plot line, using and understanding turning points. To make a story interesting for a reader, you can’t just let the characters start off with definite goals, march merrily along through the story, and then simply meet those original goals. This would be boring and not at all realistic, even for fiction. In life we set goals for ourselves and then struggle to meet them. Someone gets in our way. Something makes us try another way to reach our goal. Usually we end up changing the goal somewhat so we can obtain something loosely similar to what we originally wanted. This same experience should be true for your characters.
You need to give your characters goals, not necessarily set-in-stone goals but something they believe at the time they want or need. See the article on Understanding Goal, Motivation and Conflict. You give them motives as to why they want whatever it is and then shove obstacles (conflicts) in their path.
Turning Points are the obstacles (events, people, experiences, etc.) the characters run head-first into or stumble across on their way to meet their goals. There should be scenes leading up to these turning points, the revelation of the problem, and then scenes adjusting to what happened.
The number of turning points best used depends on the length of the fiction piece. In a longer book, having three turning points plus the black moment (the final turning point) works well. In a novella or smaller book, you might only have two turning points and the black moment. Or possibly only one major turning point and the black moment point. But even in a short story there must be at least one turning point and a black moment point or the story is too simple and boring to the reader.
As always, the article on Understanding Turning Points has been added to the Writing Tools on my website and to the Writing Tips on this blog.