I made a post last week on building believable bad guys. The flip side to that coin is creating good guys, heroes that the audience wants to root for. I think it is the case that it can sometimes be easier to write an interesting bad guy than it is to write a compelling good guy. Let's face it, nice guys can be boring to read about. That's not to say that you can't write characters that are good, heroic, or just plain nice people, but you still need to give them some conflict. You still need to make them interesting. People that are happy all the time and have no problems, they're boring (and I'm also convinced that they don't really exist).
- What do they want?
What does your good guy want? When thinking about a villain's goals, the aim is usually to set them in direct opposition with the hero. However, when thinking about the hero's goal it needs to make sense for the character and also be something that is morally right. If your aim is to create a character that people root for, someone they want to see prevail in the end, their goals should also be something that people can relate to. That doesn't mean that your character needs to be a saint, but if their goals are too ambiguous they drift into the realm of the antihero.
- Why do they want it?
As a good guy, their reasons can still be selfish. That doesn't necessarily mean they aren't a good person. However, if their reasons are selfless and morally just, you pretty much have the makings of a superhero origin story. Of course, it is often far more interesting when their motivations are deeply grounded in their personal experience. While you can certainly make your characters altruistic like Superman, it is hard to do it well.
- What is their motivation?
In the case of villains, there is usually a trauma or multiple traumas that serve as the basis for their desires. This can certainly be true of heroes as well, that trauma pushing them in the opposite direction instead. No matter what their reasoning for their desired goal, it should still be emotionally resonant. For heroes, the inciting incident can also be positive, a role model or positive moment that motivated them to pursue their goal.
- What are their limits? What won't they do?
This is, I think, a question that is particularly relevant for good guys. It is important to know what lines they won't cross. The more they are willing to cross lines, the more they exist in the gray areas that move more towards the murky middle. If your character refuses to kill people, forcing their hand can create a lot of tension and drama. Of course, people can always be pushed beyond their limits, but knowing what those limits are in the first place can help you figure out just how far you want to push.
- What would it take to make them into a bad guy?
Sometimes, we think of a good guys and bad guys as a dichotomy, but they are really more of a sliding scale. When thinking about a person and what matters to them, I always try to think about what it might take to turn them into a villain. What would need to happen in their life to shift them on the moral spectrum.
As much as villains can be more fun to write, it is generally the heroes we root for. They are often harder to write, as it is difficult to strike a balance. To make them interesting and conflicted, to set what they want against their obligations, to back them into corners where they have to contemplate their morality and their limits. It is meaty stuff, but when it is done well it can result in some of the strongest characters out there. When writing good guys, I always try to think about making them real people. Real people are out in the world just doing the best they can with what they have. That is how we need to write our fictional heroes too.