Background for your characters is important.
Let’s say you have some guy that wanders aimlessly. He seems to be someone that seems to always be in the trouble spots or the tight spots in your story/book/epic/whatever. He’s a little irritating, too. Your main character is getting suspicious because this guy always turns up at the various crime scenes rubbernecking or he’s always in the crowd when, as in the The Princess Bride, the evil Prince announces his upcoming marriage to the female lead. Or, any such other happening. You can’t help but notice him, but unless he is introduced to the reader properly, this character is just going to confuse the story.
So, in your plot, you carve out a little bit of time to introduce this character. I’ll call him Jack. Jack’s a quiet guy, but he’s had a rough life just like all the other guys in his socioeconomic class. He’s got issues, but he’s plodding along and really trying not to hurt anyone that doesn’t need it. Jack doesn’t have the best of luck and it seems that he can’t get ahead in life. He’s resigned himself to always be the overlooked. Jack gets up, does his work or whatever, and comes home to an empty house. Probably his empty house is either freakishly neat or a total dump. Jack doesn’t go out of his way to be rude to other men during his day, but he doesn’t try to be nice either. He keeps getting kicked while he’s down, so why bother?
Then one day, the female lead dashes in, and she’s being chased by a minion of the Big Bad. She is scared out of her mind and trying to get away from the minion, who has this maniacal gleam in his eye. He obviously doesn’t want to sell her tickets to the square dance. Jack looks up to see her… and stops the attack. He rescues the young woman.
That would be it for that little bit. Simple, formulaic, and you kind of want to root for the underdog Jack. You know, maybe things will start to look up for old Jack and he’ll get the girl, to boot.
But what if Jack was misogynistic like all get out? What if you had earlier in your story wrote Jack as embittered by being kicked down four times too many in life, and he hated women? Suppose all the background that you established for him didn’t match this act? Here he is, more bitter than week old coffee brewed too strong. He hates women. If it wasn’t for biological urges, he’d just as soon see them all packed away somewhere far away. And he really dislikes blondes, like two of his ex-wives. But, he saves a woman from getting kidnapped, or raped, or murdered, or turned into an undead revenant. Why?
Now, if the hero of the story was an investigative sort and found all this out, he would be seriously wondering just what Jack’s role is in all of this. He has the Big Bad to worry about, too, but Jack gives him fits. What is Jack’s secret and how does he fit in with all this? The hero is going to be thinking, and rightly so, that this Jack guy is acting out of character for what he’s supposed to be. Is he up to something?
He’s going to be wondering pretty hard about Jack.
And, if you establish the background of your characters just right, so will your reader.
In this example, there are a lot of questions that other characters are going to be raising about Jack. But, there would be no reason to be raising those questions (and therefore creating drama for your plot) if you didn’t first describe Jack in such a way that when he later saves the princess, it seems like there something about Jack’s character that no one knows – yet.
So who is Jack, really?
Finding out who he is could be a viable subplot in your story, and if executed correctly, would add nuance and all those different shades of gray that set off the main plot.
So, let’s say that the hero is chasing after the Big Bad, who’s got the princess this time. She’s fighting him and spitting and clawing and being totally disagreeable. He doesn’t care. The hero is falling behind, and the Big Bad is about to escape.
Except – that there’s a hidden sidekick that has all his demons wrestled out. Jack shows up and slows the Big Bad down enough to allow the hero time to show up.
This leads into the idea of the plot twist, which couldn’t happen without establishing a background for your characters. Take the time early in your story to do that establishing, because in the middle of the book, when your plot is supposed to be getting hot and heavy is too late. If you do character development then, except in certain flashbacks, you just mess up the tempo of the book and have to pick up the pace again.
Next up, the plot and plot twists.