Characters would be so much easier to write if they were little robots that only did what we, their creators, told them.
Wait, you may be thinking, they have to do what I want! I’m the writer!
And, technically, you could put whatever you want down on the page. Your garbage man could decide to pick up the broken broomstick and wade into battle against the menacing Witches of Wagog, but unless you’ve provided some sort of background, some sort of reason for that garbageman to become a hero for the ages (or, given his ability, a disintegrated lump of ash), your readers are going to have a hard time going along with a story. People don’t just decide to risk their lives for no reason.
Now, what happens if that garbageman has a daughter that’s been pressed or coerced into becoming one of the Witches? Maybe he’s trying to rescue her? Or, in a much more common trope, maybe the Witches are threatening the town and there’s simply nobody left to try and defend the innocent. Personally, I think the latter reason is less compelling – it robs the garbageman of his agency, to some degree. The hero is forced to defend their home or loved ones because nobody else is able to.
One of the neat things about being, well, us is that we have this nifty ability called choice. We get to decide what we do, with varying degrees of influence from outside/internal sources, at any point in time. Rather than putting the garbageman in an impossible position where choosing not to defend the town makes him a ridiculous cretin, I would say it’s a more compelling situation if the garbageman decides to go after the Witches despite not having to. In the kidnapped daughter scenario, perhaps he could chance waiting for help, but that would mean risking his daughter. In the town scenario, maybe there are others wading into magical battle and the garbageman has to confront his own fears about whether to help them or take the keys to his dump truck and run.
Lest you think this only goes for protagonists, there are these other characters in stories as well. I know, it’s a bummer, but, ideally, all of these people ought to have their own goals. Villains too.
Still, I think it’s awfully easy to miss the side characters. To stick them into rote roles, like the snarky friend or the killer-awesome pirate that excels at clearing the way for the main character. Instead, when looking at these characters, try to figure out what they want. What they need. Perhaps the karate-kicking dojo kid decides to help the garbageman stick it to the Witches because trashman’s daughter is his friend, or girlfriend. Maybe the town mayor wants to help the garbageman so he can steal the Globe of Wonderment that the witches undoubtedly possess.
You might think this is extra work, but the neat thing about determining these motivations is that they’ll help make your writing easier. Your characters, including minor ones, will start acting in scenes rather than being props to plug in whenever you need some action or someone to be rescued. The story gets color, and, best of all, we care more about the garbageman because his world is suddenly more like ours. Complicated, messy, and full of people pursuing their own ends.
Sidenote: Dark Ice went wide yesterday and is now available pretty much everywhere, which is nifty. Riven is going through edits, and the sequel is coming along nicely.