The Four Act Structure–Witches Brew or Scientific Formula?

As a scientist, I became used to the idea of formulas. It was better if things didn’t die or blow up. I learned that you had to be precise, adding just the right amount of this chemical and that liquid to get the desired product. Maybe it was fake banana flavoring or the right mixture of agar to feed the sprouting plants in my Petri dishes. Once you knew the exactly correct formula to make things work a certain way, then you could “experiment” with the formula to see if you could make things better. And sometimes things died or burned me or fizzled out.

Writing books is the same. Formulas have their place. And it isn’t until we understand the formulas that work that we can tweak them, change and bend and twist them. Sometimes they snap. Sometimes they look better twisted. When writing, I probably look more like a witch at her cauldron rather than a scientist in a crisp white coat, but the end result feels remarkably similar sometimes.

So this is the formula I use. It has evolved over the years from three acts to four, I’ve added in things gleaned from books or talks or blogs. I don’t know where it all came from at this point, and if I’ve taken it from you, please let me know so I can give you credit.

FOUR ACT STRUCTURE

ACT 1
Introduce main character (hero/heroine), their main flaw, the enabling circumstances, the opponent. The hero must be an ordinary person in this world who shows hero potential.
The life-changing or inciting incident near the beginning. (by 10%)
The lock in, or something terrible that ups the stakes just before Act 2.

LIFE CHANGING EVENT => CHOICE (around 25%)

ACT 2
The MC reacts to the life-changing event and seeks out an ally or is brought out by the ally. Ally must be established with a basic modus operandi that will qualify them to be the most well-suited person to help MC out of their predicament.
They make a plan, usu the MC’s not so great plan that sounds great but will ultimately fail because they think that they can remain the same and overcome their problem as they are. (We all want to be good enough now—but we aren’t.)
The MC struggles to hold onto flaw or not recognize it while still trying to react to the inciting, life-changing event. The MC and ally must have a confrontation.

HERO-ALLY CONFRONTATION AND FACE UP TO FLAW (around 50%)

MIDPOINT—MC recognizes main flaw. This is sometimes referred to as the the Moral Premise, where the protag stops working from a false moral premise and starts working from a true moral premise. Stan Williams has a book about this called The Moral Premise.

ACT 3
After recovering from the previous debacle, MC now fully allies with ally and prepares for the final battle/confrontation with opponent/antagonist. Of course, the opponents are rallying as well, so the stakes are increased because there are more bad guys doing more bad stuff.
By the end, it appears that failure is inevitable.

RESOLUTION OF FLAW THAT ALLOWS HERO TO CONFRONT ANTAGONIST UNENCUMBERED BY FLAW (around 75%)

ACT 4
Hero, now completely unencumbered by flaw, literally or metaphorically battles the opponent to overcome and triumph. Return to new equilibrium with better hero. (around 90%)

And because I’m a hopeless romantic, hopefully they get their HEA as well. (100%)

THE END (of the book but never the story)

There are always many ways to change this, make it unique, own it.

There are an infinite number of ideas out there waiting to become books.

I’d love to hear what kind of plotting devices you use!