Every story has its main event: quest, murder investigation, romance, competition, heist, and even the desperate attempt to stop the world ending before the villain presses a big red button that absolutely should have been better protected.
That main plot is the spine of your story which gives the audience something to follow. But if the main plot is the spine, subplots are the muscles, nerves, and slightly questionable emotional baggage that make the whole thing move.
A good subplot strengthens your main plot line, adding depth, contrast, pressure, emotion, theme, and character development. It gives your story texture and helps your characters feel like actual people with lives beyond the immediate problem in front of them.
In today’s blog, we’ll explore exactly how you write a sub-plot that works.
What Is a Subplot?
A subplot is a secondary storyline or b-story that runs alongside the main plot. It should have its own beginning, development, and resolution, but it should also connect to the main narrative in some meaningful way. That connection might be through character, theme, conflict, tone, or consequence.
A subplot can be small or large. In a feature film, it may only take up a handful of scenes. In television, a subplot may stretch across an episode, a season, or even multiple seasons. The important thing is that it earns its place.
A subplot is not just “something else happening” but should reveal character, complicate the main plot, develop the theme, raise emotional stakes, or create contrast.
If your main plot is about a character trying to win a court case, a subplot about their failing marriage could show how their obsession with winning has damaged their personal life. If your main plot is about surviving a monster attack, a subplot about two friends betraying each other could explore fear, loyalty, and what people become under pressure.
Why Great Stories Need Subplots
Subplots make stories feel richer. Without them, a story can become too narrow. The main plot may be clear, but the world around it can feel thin. Characters may have goals, but not enough emotional complexity. Scenes may move the story forward but lack variety.
Subplots help solve that as they give the audience different angles into the story. They let us see characters under different kinds of pressure. They can provide humor in a dark story, emotional grounding in a high-concept premise, or personal consequences in an action-heavy plot.
They also help with pacing. A subplot can give the audience a breather from the main conflict without stopping the story completely. In a thriller, a quieter relationship subplot can make the next suspense sequence hit harder. In a comedy, a heartfelt subplot can keep the story from feeling like a string of jokes with no emotional center.
Most importantly, subplots deepen theme. If your story is about forgiveness, your subplot can explore a different version of forgiveness. If your main plot is about ambition, your subplot can show the cost of ambition. If your main plot is about identity, your subplot can challenge who the character thinks they are.
Different Types of Subplots
There are many kinds of subplots, and the right one depends on the story you are telling.
The Relationship Subplot
This is one of the most common types. It may involve romance, friendship, family, mentorship, rivalry, or betrayal. A relationship subplot gives the protagonist someone to push against emotionally. It can reveal vulnerability, fear, desire, or contradiction.
In action films, this often gives the hero something personal to fight for. In comedies, it can expose flaws. In dramas, it can carry the emotional weight of the story.
The Romantic Subplot
A romantic subplot can create tension, warmth, humor, or emotional risk. But it should not feel like it has been dropped in because someone said, “We probably need a love interest.”
Romance should connect to the character’s arc. Does it challenge their worldview? Reveal what they are afraid of? Force them to change? Show us what they want but do not know how to ask for?
If the romantic subplot could be removed without changing the character, it may not be doing enough.
The Thematic Subplot
This type of subplot reflects the central theme from another angle. For example, if the main plot is about a protagonist choosing between success and integrity, a subplot might follow a side character who already made the wrong choice. That subplot becomes a warning, mirror, or contrast.
Thematic subplots are especially useful because they make a story feel cohesive. They allow the writer to explore the same idea without having characters announce the theme aloud like they are presenting a school assembly.
The Comic Relief Subplot
In heavier stories, a lighter subplot can offer relief. This doesn’t mean it should be irrelevant. The best comic subplots still connect to the world, characters, or themes.
A comic subplot can make the story more entertaining while also revealing character. Sometimes the funniest storyline is also the one that quietly delivers the emotional truth.
The Antagonist Subplot
Sometimes the subplot follows the antagonist, showing their plans, pressure, or personal stakes.
This can create tension because the audience knows more than the protagonist. It can also make the antagonist feel more human, more dangerous, or more thematically connected to the hero.
But the key here is not to overexplain. Mystery can be powerful, yes, but when used well, an antagonist subplot can make the central conflict feel bigger and more urgent.
The Ensemble Subplot
In TV especially, supporting characters often carry their own subplots. These can deepen the world and keep the episode dynamic.
An ensemble subplot works best when it still relates to the episode’s central idea. If every character is off in a separate story, the episode can start to feel scattered.
Balancing the Main Plot and Subplot
The hardest part of writing a subplot is balance. Too little, and the subplot feels underdeveloped. Too much, and it starts hijacking the story.
Your main plot should still drive the narrative and the subplot should support, complicate, or reflect that journey. If the audience becomes more invested in the subplot than the main plot, that is not always a disaster, but it may be a sign that your main story needs strengthening.
A useful way to test a subplot is to ask what job it is doing:
- Does it reveal something important about the protagonist?
- Does it increase pressure on the main plot?
- Does it develop the theme?
- Does it create a meaningful contrast?
- Does it pay off later?
If the answer is no, the subplot may be decorative rather than structural.
You should also look at timing. Subplots usually need to be introduced early enough for the audience to understand them, developed throughout the story, and paid off in a way that feels satisfying.
In a feature screenplay, the B-story often appears around the end of Act One or early in Act Two, once the main journey is underway. In television, subplots may be introduced and resolved within a single episode or carried across several episodes as part of a larger arc.
Focus on rhythm; the subplot should weave in and out of the main story, not vanish for forty pages and then suddenly return wearing a fake moustache and asking to be taken seriously.
Organize your storylines with Celtx Beat Sheets
Famous Subplot Examples from Film & TV
In The Hunger Games, the main plot is Katniss surviving the Games. But the relationship subplot with Peeta complicates everything. Is it strategy? Is it real? Can affection survive in a system built on violence? That subplot strengthens the emotional and political stakes of the main narrative.
In Finding Nemo, Marlin’s main plot is finding his son. But Nemo’s own subplot inside the fish tank gives the story another engine. Both father and son are learning courage from opposite sides of the ocean. Their arcs mirror each other beautifully.
In The Devil Wears Prada, Andy’s career journey is the main plot, but her strained relationships with Nate, her friends, and her own values create the emotional subplot. The fashion world is not just changing her job. It is changing how she sees herself.
In Stranger Things, the show often splits characters into groups, each with their own subplot. The kids, teens, and adults may be following different clues, but the storylines eventually converge around the same supernatural threat. That is what keeps the structure feeling connected rather than chaotic.
Common Subplot Mistakes
Adding a Subplot Just to Fill Space
A subplot should never feel like padding. If it is only there because the script felt too short, the audience will probably notice. Every subplot needs a purpose. It should reveal, complicate, contrast, or pay off.
Making the Subplot More Interesting Than the Main Plot
This happens more often than writers like to admit. If your side character’s storyline has clearer stakes, sharper conflict, and better emotional movement than your protagonist’s journey, the audience may start wishing the story was about them instead.
That doesn’t mean you should weaken the subplot but that you may need to strengthen the main plot.
Forgetting to Connect It to the Main Story
A subplot can have its own identity, but it should not feel like it belongs to a completely different project. Look for ways to connect it through theme, character choice, consequence, or plot impact.
Introducing Too Many Subplots
Multiple subplots can work, especially in television or ensemble stories. But too many can make the narrative feel overcrowded. If the audience needs a spreadsheet to remember who wants what, you may have gone too far.
Dropping the Subplot Without Resolution
If you set up a subplot, the audience expects some kind of payoff. It doesn’t always need a neat ending, but it should not simply disappear. Even a small resolution can make the story feel more intentional.
Repeating the Main Plot Too Closely
A subplot should only echo the main plot, not copy it. If the main story and subplot are making the same point in the same way, the subplot may feel redundant. The best subplots add a new angle.
Subplot FAQs
Yes, especially in television, ensemble stories, and longer features. Multiple subplots can add depth and variety, but they need to be managed carefully.
Each subplot should have a clear purpose and enough screen time to develop. If a subplot does not affect character, theme, or the main narrative, it may be worth cutting or combining with another storyline.
Not every screenplay needs a major subplot, but most stories benefit from some secondary layer.
A contained thriller or short film may only need a very simple subplot, while a feature drama or TV pilot will usually need more. The question is not, “Do I need a subplot because the rules say so?” The question is, “Would another storyline make the main story stronger?”
The terms are often used interchangeably, but there can be a slight difference. A subplot is any secondary storyline. A B-story is usually the most important secondary storyline, often tied to the protagonist’s emotional journey or relationships.
So, all B-stories are subplots, but not all subplots are necessarily the B-story.
A subplot is working if it affects how we understand the characters, theme, or main plot.
As an educational exercise, try removing it from the story. If nothing meaningful changes, it may not be doing enough. If the story becomes flatter, less emotional, or less connected, the subplot is probably earning its place.
Usually, a subplot should be introduced early enough so that it feels integrated into the story. In features, this often happens in Act One or early Act Two. In TV, it may appear in the opening act of an episode or be seeded across multiple episodes.
The timing depends on the structure, but the subplot should not feel like a last-minute addition.
Conclusion
A great subplot is the main plot’s support beam. It gives your story more depth, your characters more dimension, and your theme more room to breathe. It can add humor, tension, romance, irony, heartbreak, or pressure. It can reveal who a character is when they are not directly chasing the main goal. It can make the audience care more about what is at stake.
But like every part of storytelling, a subplot needs intention and should connect to the main narrative. It should develop over time, change something, and earn its place.
Stop losing track of your subplots—map your story’s multi-layered arcs in Celtx.
Use our integrated Beat Sheets to visualize your A, B, and C stories directly alongside your script in real-time.
Up Next:
Story Arc: What It Is, Types, and Examples from Film & TV
Subplots are the gears of a great screenplay, but they must serve the larger narrative engine. Discover how to plan a cohesive story arc that seamlessly weaves your parallel plots into a satisfying conclusion.
