Good, Evil, Lawful, Chaotic, regardless of the Kingdom, each one needed one thing.

People.

As such, it came down to the rulers of said kingdoms to implement reasons for its people to stay - whether it was something to keep people from questioning the immoral nature of their dark overlord or something to keep them from running from the kingdom filled with qrtifacys evil cults desired.

Every kingdom needs people.

Sometimes this meant adding a new law, sometimes it meant taking an old law and declaring it a law no longer. Either way, there were many kingdoms, many laws, and many a way to abuse those laws.