Question: Assume this city is relatively large by late medieval standards, around 200,000 people. The city is mainly a site for trade due to its geographically central position and being on a river. Also, because it is geographically central, it also means the city is important for the government to project power.

**What might be the benefits for this same government to sanction certain crime within this important trade city?**

Crime that would be considered legal within city limits ranges from murder, burglary, trade of illicit substances, and racketeering. This is all under the condition that the crime does not directly affect the government's activities.

Answer: 
Crime is allowed in the central city because it symbolically reinforces the government's claim to power.

* The current rulers are not nobles whose authority to lead flows down from their heritage.
* They are not great businessmen whose authority comes from their wealth and the employment opportunities they bring to the nation.
* They are not chosen by God, representatives of the divine authority of the Church.
* They were not chosen by the people.

They are conquerors, who recently attained their power by defeating the previous owners of the throne. Their power comes from their ability to overwhelm the previous symbol of law. It comes from the standing army which they brought with them, warriors who are now free to commit whatever crimes they wish in payment for their services. Justice has fallen to their might.

But they are also not fools. They know that if lawlessness is allowed throughout the kingdom, then the kingdom will very quickly fall. So outside of this city, the law is enforced even more brutally than it was under the previous king.

But here in their new home, strength is the only law.
**All of that is already legal to some extent in some places**

Legal in lots of jurisdictions, some of them even real democracies:

* Killing humans, for example in self defense, in war, as capital punishment, to save the mother of an unborn, abortion or euthanasia.
* Substance trading and consumption: Drinking alcohol, smoking tobacco or cannabis
* Taking other people’s property: Taxes, fines, fees, interest, foreclosures

The most important part is that the above activities are tightly controlled in order to provide stability and reliability. A successful city or country generally needs stability. You certainly don’t want random murder on the streets to be legal or you’d have anarchy and mayhem. But as long as it’s controlled and restricted in some way it’s perfectly feasible for murder to be legal. Even if it’s just some amount of money (“tax” or fine) you have to pay to the government for committing certain things.