What Is a Subplot? Types, Examples, and How to Keep Subplots Alive in a Long Story

A subplot is a smaller storyline that runs alongside the main plot. It usually follows a supporting character or another side of the protagonist's life, and it earns its place at the moments it collides with the main plot.

This guide covers what a subplot is and how it differs from the main plot, the three jobs subplots do, five common types with examples, and the order for weaving them in. It also covers a problem most guides skip: in a serial that runs for hundreds of chapters, side threads tend to quietly disappear. There's a tracker at the end to stop that from happening.

At a glance

The main plot follows what the protagonist wants. A subplot follows a different relationship or character beside it
A subplot is useful when it meets the main plot. One that never meets it can be cut
Decide where each subplot starts, where it meets the main plot and where it ends before you write, and weaving gets much easier
In a long serial, note the last chapter each thread appeared in, and bring it back briefly before it's been gone too long

Subplot definition: a smaller story beside the main one

A plot is the chain of events, linked by cause and effect, in the order you choose to show them. Most novels carry several of these chains at once. The one that follows what the protagonist wants and decides how the book ends is the main plot. A smaller chain that starts and ends on its own beside it is a subplot. You'll also see it called a secondary plot or a side plot.

Subplot and B-story. In Blake Snyder's Save the Cat! beat sheet, the B-story is the second storyline that begins early in Act Two, often a relationship, and carries the theme the protagonist needs to learn. The B-story is a subplot, usually the most important one. A book can have several subplots, but in that model it has one B-story.

TV writers use a similar shorthand. An episode's A-plot is the main story; the B-plot and C-plot are smaller ones cut in between. The idea is the same in a novel, except that a novel's B and C threads can run across dozens of chapters.

Main plot vs. subplot

	Main plot	Subplot
Who it follows	The protagonist and what they want	A supporting character, or another relationship or feeling of the protagonist's
How much space	Most of the book	A scene every few chapters
When it ends	At the ending	Before the ending, or together with it
If you cut it	The story falls apart	The story survives but feels thinner

The last row is the most useful test. Take a thread out: if the ending still works, it's a subplot. If it doesn't, it's part of the main plot.

What a subplot does: three jobs

1. It shows the theme from another angle. If the main plot is about “what you do says more about you than the name others give you,” a subplot can put the same question to a different character. A character who answers it the opposite way from the protagonist makes the theme clearer.

2. It controls the pace. When the main plot hits hard for several chapters in a row, readers tire too. A lighter subplot chapter after a tense one gives them a breather. When the main plot is quiet, something happening in a subplot keeps the tension up.

3. It changes what happens in the main plot. This is the most important one. A relationship or clue that grows in a subplot should help solve or complicate a crisis in the main plot. Without that link, readers treat subplot chapters as chapters they can skip.

Types of subplots

Here are five common types. The examples come from They Say I'm a Dark Mage, but All I'm Good At Is Digging Dirt, the story used in TypeTak's Web Novel Course. Its main plot: Clay, an earth mage mistaken for a dark mage, holds on at the academy and finally makes a place for earth magic.

Type	What it follows	Example
Relationship (friendship, romance)	The distance between the protagonist and one character	Mia, the only friend who knows Clay's real element. Each time the misunderstanding grows, she cleans up after it, and the two grow closer
Rival	How an opponent changes	Lucian, a noble, competes with Clay while secretly afraid of him, and every time he pushes back he only raises Clay's reputation
Mentor or ally	What the guiding character is really after	Seraphine, the dark magic professor, keeps setting Clay dangerous tests to confirm his power
Mystery or setup	A question still waiting for an answer	Soil Clay restored goes bad again a few days later. In Part 3 it leads to the traces of Barkan, the real dark mage
The protagonist's inner conflict	A feeling the protagonist carries alone	Clay's goal of earning a certificate to support his family, pulling against the expectations growing around him at the academy

A mystery subplot sometimes rises into the main plot late in a book. The soil that keeps rotting is a small setup in Part 2, but in Part 3 it drives the whole story.

Other types you'll see in craft books (revenge, a secondary character's arc, a family thread) fit inside these five. What matters is less the label than whether the thread has a question and an end.

How to write a subplot, step by step

Write subplots after the main plot is in place. It takes five steps.

List the big events of the main plot. Once you can see how each part ends and where each arc hits its crisis, you'll see where subplots can slot in.
Give each thread one question. “Will Mia keep the secret to the end?” “When will Lucian admit Clay is better?” It should be something readers wait to see answered. A thread with no question isn't a subplot; it's background.
Decide where it starts, where it meets the main plot and where it ends. Those three points alone keep a subplot from wandering. Place the meeting point at a crisis in the main plot for the biggest effect.
Tag your arc outline with thread names. For each arc, note which subplots take a step forward. Kishotenketsu shows a three-layer outline (story, arc, chapter) you can use for this.
Check the endings. For each thread, confirm the question gets answered, and decide whether it closes before the main ending or together with it.

Subplot examples from one story

Here are four of the five types set up as threads. The chapter numbers are examples chosen for this guide, based on a serial of about 150 chapters.

Thread	Question	Starts	Meets the main plot	Ends
Mia	Will Mia keep the secret to the end?	Ch. 2: Mia says quietly, “You're an earth mage, aren't you.”	Ch. 42: before the public practical, she stops Clay from using an earth golem / Ch. 141: while Clay is unconscious, she handles the misunderstanding alone	Ch. 150: Clay reveals the truth himself, and Mia no longer has to keep the secret
Lucian	When will Lucian admit Clay is better?	Ch. 7: in the first week, he almost challenges the “dark mage” to a duel, then backs off	Ch. 41–45: he overreaches with a spell and brings down a wall in the practice yard	Ch. 140: he dumps a basket of rotten soil at Clay's feet. For the first time, they work together
Seraphine	Will Seraphine find out who Clay really is?	Ch. 12: “From today, you belong to my lab.”	Ch. 44: she takes the dust cloud over the practice yard for a major dark spell / the conflict over the lab	Ch. 150: told he's an earth mage, she's delighted that he's “even more worth studying”
The soil that rots again	Why does restored soil go bad again?	Ch. 34: the flowerbed soil turns dark again three days later	Ch. 58: Mia points at the same spot / Ch. 96: land near the academy is found rotting the same way	Becomes the main plot in Part 3

All four threads meet the main plot at its crisis chapters (41–45, 96, 140). The Mia thread also carries into the chapter after the climax where Clay pays the price, so the subplot fills a gap in the main plot.

Why subplots disappear in long serials

A reader gets through a printed novel in a few days. A web serial comes out one chapter at a time. At a chapter a day, chapter count is day count: if Lucian is gone for 30 chapters, readers haven't heard from him in a month.

Subplots usually vanish in a serial for three reasons.

The main plot grows and squeezes them out. The harder the main plot hits, the more you postpone subplot chapters, and a postponed thread is hard to pick up again.
You forget where you left them. With more than four threads, you have to dig through the manuscript to find where Mia's story stopped.
You follow reader reactions. You grow the thread readers love, and the others stop with their questions hanging.

There's no fixed rule, but on a daily schedule a thread that's been absent for close to a month is easy for readers to forget. Bring it back briefly, even with one line of dialogue or a passing moment inside a main plot chapter. When comments start asking “where's Mia?”, that thread has been gone too long.

Subplot tracker template

Copy the box into a notes app or document and fill in one block per thread. Each time you post a chapter, update “last appeared” and scan for threads that have been gone too long.

Subplot tracker

[Story]
Title:
Planned length: (___ chapters)
Current chapter: (___)

[Subplot 1]
Thread name:
Character:
Question:
Started in chapter:
Last appeared in chapter:
Next planned appearance:
Meets the main plot in chapter:
Ends in chapter:

[Subplot 2]
Thread name:
Character:
Question:
Started in chapter:
Last appeared in chapter:
Next planned appearance:
Meets the main plot in chapter:
Ends in chapter:

[Subplot 3]
Thread name:
Character:
Question:
Started in chapter:
Last appeared in chapter:
Next planned appearance:
Meets the main plot in chapter:
Ends in chapter:

Common subplot mistakes

The subplot gets more interesting than the main plot. If readers skim main plot chapters to get to a subplot, check whether the subplot has picked up the main plot's question.

Before: Lucian's thread grows into a succession fight in his family, and Clay doesn't appear for more than ten chapters.
After: the succession fight shows only as pressure on Lucian (“beat the dark mage and earn your place”), and that pressure explodes as his reckless spell at the public practical in Chapter 41.

The subplot vanishes instead of ending. A thread that raises a question and stops without an answer stays with readers as a loose end.

Before: Seraphine stops appearing after Part 2, and we never learn whether she finds out who Clay is.
After: in Chapter 150, Seraphine is in the room when Clay reveals the truth, and she answers in one line: “Then you're even more worth studying.”

The subplot never meets the main plot. A subplot that reads the same when lifted out of the book can go.

Before: several chapters follow Mia preparing for the academy festival, with no connection to Clay's misunderstanding.
After: while preparing for the festival, Mia hears a rumor about an earth golem and moves to contain it first. Her thread now meshes with the main plot's misunderstanding.

Keeping subplots on track in TypeTak

TypeTak is an AI writing editor where you write alongside an agent. When you're running several subplots, what you want is for each one to keep going and end where it should.

See which thread has stalled, and for how long. Lay out events as chapter cards on the Board, and each card carries the characters in it. Line them up by character and you can see at a glance whose column, Mia's, Lucian's or Seraphine's, has been empty for a while.
Count appearances per part and chapter. You can see how many events each character appears in per part and chapter, so you'll notice when a thread is bunched up in one place.
Keep the order a character changed in. How a character has changed along their subplot builds up in chapter order, which makes it easier to decide where to take them next.

You can find a stalled thread without rereading the manuscript from the start, which cuts the time it takes to run the tracker above. When a thread goes missing for good, it can turn into a plot hole; What Is a Plot Hole? covers how to find and fix those.

FAQ

What is a subplot?

A subplot is a smaller storyline that runs alongside the main plot. It follows a supporting character or another relationship of the protagonist's and adds depth when it meets the main plot.

What is an example of a subplot?

In a story about a misjudged mage surviving an academy, the friend who's the only one to know his secret is a relationship subplot, and the rival who keeps trying to beat him is a rival subplot. Both start, grow and end on their own, and both collide with the main plot at its crises.

How many subplots should a novel have?

There's no set number. A short story usually has one or two at most, while a novel or long serial tends to have about as many as it has major supporting characters. More important than the count is whether each thread has a question, an end and a point where it meets the main plot.

Does a subplot need its own three-act structure?

Even a short beginning, build and ending helps readers remember it as a thread of its own. It doesn't need the tight structure of the main plot. Three points (where it starts, where it meets the main plot, where it ends) are enough.

Do short stories need subplots?

Not necessarily. A short story often works best with the main plot alone. If you add one, keep it to a single subplot and resolve it inside the same scenes as the main plot.

Sources

Subplot: Wikipedia — Subplot
B-story: Blake Snyder, Save the Cat! The Last Book on Screenwriting You'll Ever Need (Michael Wiese Productions, 2005)