Subplot

In fiction, a subplot is a secondary strand of the plot that is a supporting side story for any story or the main plot. Subplots may connect to main plots, in either time and place or in thematic significance. Subplots often involve supporting characters, those besides the protagonist or antagonist.

What is a subplot?

The plot is simply what happens in a story. So, a subplot is what happens within what happens. 

In other words, a subplot is a smaller story within the larger, overarching story. The subplot may or may not be crucial to the structure and coherence of the broader actual plot. 

Usage

For your reference, here are some examples of the term subplot being used correctly within the context of actual sentences. 

"The critic argued that although the subplot in the film seemed somewhat irrelevant at first, it actually contained the key to unlocking the deeper meaning of the work as a whole."

"Although the author wanted to include several subplots in his work, the editor convinced him to cut at least some of them, on the grounds that the average reader would never be able to follow them all."

"The novel contained subplot after subplot, to the point that the reader began to wonder whether the writer had been drunk or otherwise distracted when he had been producing the work." 

In case you're still unclear about the meaning of the literary term subplot, here are a couple rules you can follow when using the term. 

1. The subplot is always embedded within a broader main plot. A subplot generally follows a side or peripheral character within a story, as opposed to the primary protagonist of the literary work. The side character becomes a kind of "sub-protagonist" within the subplot. 

2. The subplot generally adds richness to the main plot in terms of theme and perspective. However, it may not be essential per se to understanding the literal plot itself. However, the subplot may be crucial for understanding the themes and meanings of the work at a deeper level.

Subplots in literature

The literary interest in the device of subplot is perhaps based on the basic awareness that every person is really the hero/heroine of the story of his/her own life. That is, for every story in which one given person is the protagonist and others are side characters, it would be possible to tell several stories in which those side characters become protagonists and the protagonist becomes a side character. The hero is the hero from a certain standpoint only. The use of the subplot thus enables an author to achieve a broadening and deepening of perspective. 

Sometimes, it can actually be difficult to tell the difference between the main plot and a subplot within a work of literature, due to the fact that several different plotlines may in fact run parallel to each other and have a strong mutual influence on each other. In this case, the term subplot may not technically apply, due to the fact that there is no main plot relatively to which the subplot can be called a subplot; rather, there would be a kind of convergence of plots that could perhaps be said to produce a kind of meta-plot. In a way, this is reflective of the history of the human species: the stories of countless individual lives weave together in order to produce the story of the species as a whole.