Header / Cover Image for 'Writing Tip: Plot Expansion'
Header / Cover Image for 'Writing Tip: Plot Expansion'

Writing Tip: Plot Expansion

Many writers, at some point, learn about story structure. The idea that stories are most effective if they follow some common rules, such as delivering on what you promise to the readers. If you start a story with people plotting to kill the king, you better have the king either killed or saved by the end of the story. If you write a book promising dragons, they better show up at some point to do cool stuff.

This, however, begs the question: won’t that make the story completely cliché or predictable?

If you clearly promise something at the start … then dutifully deliver that … there isn’t much in the way of surprise or plot twists left. The major draw of stories—the need to find out what happens next—is entirely gone.

Some time ago, I came across the word “plot expansion” as a solution to this. (Which I think is credited to Brandon Sanderson.)

Back then, however, I didn’t really understand. You just … bolt an extra storyline onto the thing you promised? You start the book with a plot to kill the king, but then halfway you suddenly add this whole romance thing? Doesn’t that still break promises and feel unfulfilling?

After writing many books and short stories the past years, I gained a better understanding. I realized this with a story I just finished, which is why I write this article.

Plot Expansion isn’t “necessary”

First of all, plot expansion isn’t “necessary”. The idea of a promise (in story terms) is that you tell readers what they can generally expect, but nothing else. Not the how or the why or the who.

You promise readers a plot to kill the king. But why are they doing it? Who is doing it? How will this unfold? That’s all answered during the story.

You promise readers a fight between good and evil. Surely, good will win, as they always do. But how will they win? At what cost? What’s left in the end? Which of these nice characters will survive?

At the same time, even those variations and specifics have been done countless times before. People these days have read books, seen movies, binged shows, so a generic setup like “good fights evil” probably won’t bring anything new to the table.

Harry Potter was the biggest success imaginable. Writing a story with a magic school nowadays will mostly be received with “meh, you just copied Harry Potter”.

(Though it’s still a popular and successful subgenre, particularly with younger kids. And Harry Potter itself was obviously also copied from works before it. I’m not really stating that people are logical or that this makes sense, I’m merely focusing on the reality of the situation when creating stuff to be consumed by other people.)

That’s when plot expansion comes in.

In marketing terms, I think your best approach now is to write a different intriguing story with only a vague hint of a magical school. You deliver your original promise, sure. But as the book goes on, that part about the magical school grows and grows. It never overshadows the original idea, it never becomes the main thing, but it blends with the original storyline to deliver more than the reader expected.

In many ways, this is what Rowling did. The first Harry Potter doesn’t start with tons of magic, or an introduction to the wizarding world, or anything like that. It starts with a mysterious conversation and an orphan boy leading a curious life for several chapters. It hints at the magic school, but the importance of that only grows as the book goes on.

You start reading Harry Potter to find out about this mystery and this boy. You end up enjoying it because it’s much more than that in the end.

My current definition

So, how would I define plot expansion right now?

  • The first chapter of a story clearly outlines the main goal we’re working towards, while (very vaguely) hinting at other elements that might be there.
  • As the story makes progress on the main goal, the other elements grow in importance and detail.
  • Until they weave together to form a slightly changed main goal.
  • More and more …
  • Until the end of the story doesn’t break your promise, but is still different and more than the reader expected.

The idea isn’t that you bolt random stuff onto your original plot. The idea isn’t that you swap it out halfway. The idea is that you introduce new elements that are allowed to “taint” the original promise into something more than it was.

(As always, I write these writing tips as I discover or ruminate about them. My views, principles, ideas, all change over time. As is evident when I write tips that replace or contradict older writing tips.)

I’ll give you the example from the story that made me realize this. (Spoilers, of course!)

Saga of Life: The Run of Bar-Bar

This is story #5 of cycle #3 from the Saga of Life. It’s about the Romans and Barbarians.

Currently, the king of the Romans has gone mad. The story starts by showing some weird and dangerous commands the mad king is putting out, and how they hurt the people.

As such, some masked figures visit the Barbarians to ask them to do a mission: assassinate their leader. (This was actually a thing. The Romans looked down on these Barbarians for their anarchist way of life … but also hired them whenever some “dirty deed” needed to be done. The Romans wanted their pretty hands clean.)

It’s a clear goal. A clear promise. This will be a story of trying to break into the palace and kill the mad king.

But then …

  • It’s revealed that these masked figures were the king’s own sons.
  • Which leads into the reveal that they use the “mad king” thing as a guise for wanting the power themselves.
  • Which leads to a fight between the sons about who gets the throne, where one kills the other.
  • Which turns the mission into “kill the king AND his sons”, which the Barbarians are hesitant to do.

Halfway the story, the mission has become slightly more, because of the other storylines. You’re still getting what was promised, just with slightly more asterisks.

The story continues …

  • The eldest son (who’d get the throne if the king died) blatantly ignores their own lawbook when a clever lawyer almost legally deposes them. (This is the second storyline of this story: a legal battle by someone who wants to legally get rid of the mad king. They truly believe it must be done that way and actually stop the Barbarians, with pleading and logic, the first time they try to do the mission.)
  • It’s revealed that the Romans have secretly been handing money/weapons to another Barbarian tribe (the Huns) that is now hunting down our protagonists. This puts a metaphorical time bomb underneath it all.
  • This shows the Barbarians that they must act now and they must get rid of the entire corrupt royal family.

By the time they enter the palace to finally do it, their mission has changed. More characters are involved. There’s a slightly larger goal which is harder to achieve. At the same time, meeting that lawyer made them doubt whether just killing someone they don’t like is even a good thing.

It’s still very much a story about breaking into a palace and killing a mad king. But it’s also about these other things, and there are more objectives in the end and more ambiguity about what will happen.

A tiny mission turned into a larger one. A tiny problem turned into a huge one. Each storyline eventually blended with the main one to irrevocably “expand” it.

When your only promise is a mission to kill the king, it can only end in two ways. Either they succeed (“well, that was to be expected”) or they fail (“then what was the point of this story!?”). If you expand it to have multiple facets, multiple angles, multiple reasons, the story can still be surprising because it can go so many ways.

They can achieve part of the mission. Some characters might not make it. They can have dilemmas or discussions about how to go about it. Way more variety in possible endings for the story.

This wasn’t done on purpose. I just write stories—at least the initial drafts—as they come. It was only when I wrote the last two chapters that I realized how much the original promise had expanded. And how that felt like a very good thing.

(So good that it led to too much story, forcing me to cut a lot of words in the revision to stay underneath my upper limit of 15,000 words. Beyond that, I’m not comfortable calling these short stories anymore. Besides that, it’s mostly an arbitrary limit that seemed to work for the first ten stories.)


I hope I explained this well enough. I’m still figuring this out as I go.

The general idea is simply that a story should always have one main, core promise. This is the main storyline and you should deliver on that promise.

But add other storylines that, over time, blend with the main one. This causes it to change, to grow into something bigger, to involve more characters or ideas.

So that by the time you need to end a storyline, there are suddenly a thousand ways to deliver that promise. There can still be unexpected twists and the readers can still be surprised. Even better, the whole journey of reading the book doesn’t feel like a waste, because the ending was already set in stone from the start.

I’ve seen this reflected in some other theories about story structure that talk about “accelerating the plot”. Usually, they pick the midpoint (or 33% and 66%) for some big event that “expands” the plot. For example, a story has been about finding a long lost sister, and then BAM it turns out they were long lost twins. The general idea is the same, but now you’re suddenly searching for two long lost people. Plot expansion.

That also feels like a useful way to look at it.

That’s all,