Originally Posted by
Toastkart
Simply stated, a crime is any act that breaks a law. Laws can be written for many different purposes, many of which have nothing to do with morality and everything to do with power. Even if you're not writing in the fantasy genre, it can be helpful to research laws written in the middle ages, purely for idea mining. There were laws about who could carry weapons, what kinds, when, etc. There were laws about who could wear what kinds of clothes, of what materials, etc. There were laws of inheritance, marriage between people of different social status, settling disputes, and all sorts of other things. I'd be hard pressed to call these laws corrupt, contrived, or nonsensical so much as arbitrary outside of the context of maintaining power for a particular cultural group, or the social hierarchy they've created.
It may also be helpful to think not just of laws but also of regulations, ordinances, decrees, and precedent. Going against precedent may have a lot of implications, but it may also be the most powerful way to enact change. Defying the decree of a king, no matter for what reasons or for how right the character thinks they are, may result in imprisonment, public execution, or quietly being put away just because the king can't afford to look weak no matter his personal feelings on the matter.
Speaking of cultural groups, laws can be applied more strictly to some groups than others. Here I'm not even talking about real world political issues (which we should stay away from) but more about communities and who they think belongs and who doesn't. As an example, my dad once bought a firetruck and kept it in his driveway for a couple weeks. He was served a notice stating that it was against city ordinance that a commercial truck be parked in a residential area, even though another guy a few streets over (in the same subdivision) had been keeping a semi truck in his driveway for years and still does to this day.
To bring this to a close, if you can think of an action, someone somewhere has probably tried to make a law to prevent it. Laws aren't written from a place of moral authority. Laws are written to exercise power and create and maintain a culture. Evil has very little to do with it.