One of the biggest challenges a writer will face is to create a well-rounded, believable character. You need to make it believable, from the most insignificant childhood memory to the little quirks that will drive you, and your readers, crazy. It’s tempting to make them perfect at everything. Smart, funny, athletic, emotionally capable; all of the things that no real person can ever be.
We want our protagonist to be fit for the job, so that nothing ever holds him or her back. But in reality, very few people are like that. We all have our own personal thoughts that will hold us back from doing things so that we are more cautious than others or more inclined to laugh. All of these can be traced down to childhood memories. We laugh to hide the pain of parents that worked when we were younger or we’re more cautious because of continual failures in school. A person’s childhood can shape who they become so when you give your character a particular quirk, ask yourself why. Even if it never makes it into your story, it will help you to better understand your character and make them lifelike.
Another thing that is important to remember is that everyone has a vice. We procrastinate, gamble, or drink; we are more prone to succumb to anger or tricks. Giving your character a few of these makes people more able to understand them.
For instance, let’s say that you have a particularly smart character. He annoys everyone else with how smart he is but they put up with it because he is a loyal friend. The problem, though, is that he is often bored. Nothing in the world excites him anymore because he is hard to surprise. In his desperate search for intellectual stimulation, he turns to gambling and has been known to lose track of time doing it. He avoids card games because he has been caught counting cards a few too many times and it is too easy for him, so he turns to dice games.
Now, he may not be your protagonist but your side characters need depth too. Having a clumsy spy, a drinking diplomat, or an easily angered knight can be amusing for your readers and it will give your story a bit more depth. Don’t be afraid to have your character break their stereotype.
But what about your main character? How can she be an alcoholic or an excessive gambler? Well, she doesn’t need to be. Sometimes vices can be unexpected, like too easily trusting people. If you give your protagonist this vice then you offer a chance for betrayal, which will spice up your plot. Maybe she loves solitude so she goes to investigate something alone and is then ambushed. Your vice doesn’t always need to be bad but your protagonist needs something that works against the profile of hero. And don’t be afraid to have more than one. The more flaws, the more lovable the character.