My various conversations in comments have led me to what could be a useful answer.
Governments, all governments, have only one method of enforcement: violence
The threat of violence, of course, need never bear fruit. A small group of people can agree to behave according to a set of rules and, never breaking those rules and never seeing the threat realized.
But once a rule is broken the threat must be realized lest the governed forever walk all over the governors.
The dynamics of this situation are enormous. I'm sure whole books have been written on the subject, so I'm only going to touch on the matter.
The U.S. Declaration of Independence defined four truths, only three of which were then defined as unalienable (inseparable from the human condition) rights:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
This staetement is reasonably inclusive of all the methods a government can use to enforce laws.
- Life: imprisonment, execution, etc.
- Liberty: fines, escheatment, etc.
- Pursuit of happiness: exile, deportation, etc.
- Equality: Ah... equality.
Have you ever noticed that passing strong drunk-driving laws is painfully difficult? That's because (a) most people like drinking liquor and (b) most legislators don't want to be held accountable to the law. Laws governing equality have the same problem, which is undoubtadly why equality wasn't included as an unalienable right in the U.S. Declaration of Independence — an observation that appears to be validated by the infamous Three Fifths Compromise leading to treating slaves as 3/5 of a human for the purposes of counting population when determining representation.
Why the history lesson? Because equality is the fundamental threat when it comes to enforcement. You are being made unequal to everyone else because you won't follow the rules.
The ultimate threat of violence in a slave-holding society: slavery
Which suggests the easiest way to keep everyone in a slave-holding society in line is to threaten them with becoming slaves themselves. Culpae poenae par esto — let the punishment fit the crime.
The problem is not enforcement, but consistent enforcement
The U.S. trial of Eliza Rowand in 1847 makes a strong point. No law is of intrinsic value. Government as a profession is a cost to a nation, producing nothing. An ideal society needs no law — but people will always have a difference of opinion, which requires law to resolve the inevitable argument.
In the cse of Eliza Rowand, despite the existence of slave codes that gave considerable bearth to slave owners as to how slaves could be treated, when accused of murdering a slave, she was nonetheless aquitted.
The judge and jury refused to uphold the law.
Law is ultimately an exercise in social force
The issue here is how you organize your society such that it can do its level best to happily operate within the confines of law.
The People will always want protection over the forces that can subdue them: government, business, and their neighbors.
Business will always want protection from those same forces.
Government, itself, will too.
You see, all it takes is one person who thinks slavery is wrong and you suddenly have an activist working to create a minority voice within your government — someone who wants to change the law and will often advocate resistance to, if not outright defiance of, the law. The result is rules within rules, balancing the need for power to change law as circumstances change with the need to restrict that same power so rules aren't changed when they shouldn't.
And, of course, no one can agree on where the line is between those two forces.
So, as you develop your world's legal system, remember that nothing's perfect and, when it comes to government, nothing's simple. How can you enforce those laws?
- You need investigators
- You need enforcers
In the criminal justice system, the people are represented by two separate yet equally important groups: the police, who investigate crime; and the district attorneys, who prosecute the offenders. These are their stories. (Law & Order)