There is an eternal law, inscribed into the very essence of the universe before even the gods came on the scene, that any home improvement project will require at least three trips to the store.
Don't believe me?
Many creation myths show the gods making several attempts before we get the world in which we live. Even the book of Genesis has a do-over with Noah.
Many stories are basically a series of try/fail cycles.
Consider the archetypical home improvement project:
- Having decided to undertake some repair or improvement, you go to the store and get what you need.
- After working on the project for a while, you make another trip to the store to get all the things you didn't know you needed.
- Finally, a few injuries and explicatives later, you make a final trip to the store to get what you really need (as well as to replace the pieces you broke).
For a story to be interesting, it must show how the protagonist triangulated on a solution to a difficult problem. It's like the process of artillerymen finding the range to a target: the first shot falls short so they increase the elevation; the second shot lands behind so they dial back, but not as much as the first setting; the third shot is much more likely to hit.
And suddenly, without trying, we've discovered the three-act story structure: try/fail (act 1), try/fail (act 2), try/succeed (act 3). Each try is a possible solution and each fail shows why the solution falls short as well as ratcheting up the scope of the problem. In the realm of DIY, for example, you fail to reattach the loose tile in the bathroom because the wallboard behind has water damage, but you can't just replace the wallboard because the pipe inside is leaking.
If you scrape away all the formal baggage around, "The Three Act Structure," it really is that simple.
[That said, like any good DIY project, there's a big gap between the theory and actually putting it into practice in the form of a finished novel.]
Image: Simon Howden / FreeDigitalPhotos.net