How to Develoop B-Plots

Most writers have no problem with A-plots. Even pantsers have no problems with their main plots; they may wander, but they have a pretty good idea of where they are going. However, it's the B-plots, the secondary threads, that most writers have a problem with. The problem is pretty simple: They just aren't as pretty as the longer and more convoluted main plots. Some writers even forget that B-plots serve a pretty useful purpose. It is thus pretty important to include some secondary plots in your story.

The Purpose of B-Plots

The A-plot is pretty busy: Not only does it need to deal with the primary and possibly secondary conflicts, but it also needs to get the protagonist and his group to the points where they need to be. In a film script, it gets almost half of the scenes that a writer allocates to the script. However, there are still plenty of problems that need to be dealt with, from romantic subplots to competition between characters to just following important objects from one point to another. In some cases, the writer may want to include some sort of running gag.

These are all handled best through B-plots.

B-plots allow writers to give secondary characters some spotlight, deal with issues that just don't fit in the main plot, and help develop the characters a little more. In movies, this is when you move away from the A-plot and explore the other parts of the world. The romance is usually a B-plot, as is the main character working on his promotion. In the teen sex comedy, the boys trying to get laid are each in their own B-plot while they're dealing with the corporate raider in the main plot.

While they may feel like filler, they still move the plot forward, either by building up the characters and making them better able to deal with the threat at hand or by ensuring that events move along. Sometimes they just help the pacing of the story by giving you a chance to let things stew as you explore other aspects of the world. They can do a lot of heavy lifting by filling in holes that you just can't get to in the main story.

Writing In the B-Plots

When you're outlining your story, the A-plot should take up about half of the scenes while each B-plot should take up a fourth each. This means that for a 60-scene movie script, the A-plot should have 30 or so scenes on its own while the B-plots should have about 15 each. While this number can vary, it's advised that you don't change it all that much; adding too many scenes will encourage writing just to fill space while taking too many scenes away will cause pacing issues.

Yes; you're going to want at least two of them. You're going to find that sub-plots tend to help your story's pacing as well as cover issues that your main plot doesn't. This means that they can cover plot holes, build up characters, and even allow the characters some fun. With that in mind, having two of them running around will add more dimension to your story, making it more complete. However, you don't want more than three as it may make the story too complicated; combine planned sub-plots when possible. If you need to, reserve some scenes for C-plots, which are generally collections of scenes with their own rules; these are best used for montages or running jokes.

Each plot should be treated as its own story for purposes of determining its instigating point and climax. However, when you combine them into the master outline, don't worry too much about them meshing up. It's entirely possible for one of the B-plots to not even start until after the instigating point of the main story and the other end well before the climax; these are meant to enhance the story, not drag it down, so pace them as it feels best for the story.

When you do fold them into the main plot, there are just three things to remember:

•  Remember that they are best used to help the pacing of the story. There will be times when letting things stew or giving characters time to get from one location to another will be needed, as well as times to worry about other parts of the story. This is where you need a B-plot scene.
•  You can combine scenes into bigger scenes. This means that you can have two characters flirt (romantic subplot) while other characters find a clue (knowledge subplot) during the big dance scene. This will likely involve lots of little scenes, but it will make for a fun chapter. 
•  Unless you're combining them, try not to follow one scene from one plot/subplot with another scene from the same plot/subplot. It will just help your pacing.

Some Ideas for B-Plots

Romance: The obvious one, this does not need to involve the protagonist. It can feature characters that need to be developed, such as the prince and princess forced to marry for the good of the kingdoms or the sidekick and his wife.

Relationship Building: The main plot is concerned with bug events, but sometimes you need some small events to help develop characters, such as a father rebuilding the relationship with his daughter or a bishop with his flock. This subplot allows you to focus on those relationships.

Personal Emotional Growth: Pretty much a catch-all, it can be important for even heroes to develop as people and they can't always do this in the main plot. This allows them to pass into the shadows and engage in small but important actions.

World-Building: You may want to explore the history of the world, look at the local festivities, see how the little people are living their lives, or even explore some local geography. These subplots help build your world up and flesh it out a little, becoming important on their own.

Training: Characters need to get better and so they need to train. These subplots help your characters get better without interfering with the main plot but while fulfilling the main plot. If the protagonist needs a particular skill, this helps him get it.

Research: Sometimes you need to send a character to the library or the local dragon in order to track down some information. This allows you to have some fun with that and shows that sometimes getting the information for the quest can be as hard as the quest itself.

Competitive: This is more of a running gag, but having two or more characters involved in a competition that has nothing to do with the main plot, such as baking the perfect pie, building the best racer, or even a prank war can be great to just have fun, especially if the main plot is way too serious.

Travel: While there may be a lot of travel involved in the main plot, this has more to do with the travel itself, such as the problems with riding animals or vehicles, obtaining permits and tickets, or even just making sure that the group doesn't get lost.

Favor Chains: Sometimes doing a quest means getting someone to do something they don't want to do, and it requires a chain of actions to make it happen. Since you don't want to follow this chain of events in the main plot, assign it to a secondary character and go with it.

Following an Object: Sometimes you need to follow an object of power's location or its origins. This helps your world-building and shows the effect of your object. You can apply this to animals or even characters, such as an immortal whom you want to flesh out his history a bit.

B-Plots Can Only Help

Side plots can do a lot of heavy lifting and add some much-needed levity to an otherwise heavy plot. They should be used to keep the plot going, so don't get too bogged down in them. However, if used correctly they can add so much to the story, and turn an otherwise boring, straight-forward story into a roller coaster, vastly improving your story.