D – Dungeons/prison, jail
Any large city will have a means to imprison law breakers and trouble makers.
A large enough city might have district jails for local/petty crimes, and a main prison for major crimes.
A prison could be an above ground structure, such as an island in the middle of a harbor with a tower.
It could also be a dungeon under the governor’s palace.
Some prisons can be intentionally imposing structures with a design aimed at intimidation and fear. Perhaps stone lions that come to life when there is a prison break. Maybe they have gargoyles that are bound to serve the warden. Jet black stone construction of sheer walls of an unusual height, with towers and battlements, and big, mean, tough guards on patrol. Magical wards to prevent magical ingress or egress, rooms with detect lie, or perhaps just the interrogation chair has that ability, so that the interrogators can lie. Huge banners flying with the insignia of the prison.
Are there pits where the worst prisoners are just dumped and forgotten, like a series of oubliettes?
Depending on how “nice” the government is, there could be shackles on the walls, torture chambers, a gallows or chopping block.
Some types of crimes might warrant putting someone in stocks in the local square. Public shaming was a formal type of punishment that lasted into colonial times in North America.
Is there a secret police? If so, do they wear a uniform so that everyone knows who they are, and fear them and listen to them out of fear?
Is there a standard uniform for constables? Does the city guard perform all policing functions? Is there a difference between the city guard and the army? In the Wednesday night online AD&D game I play in, one city we spent time in has different districts of the town controlled by different factions. Each faction has their own city guard for their area. It is sort of a miniature confederacy in the same city.
Are there any magical items to aid in enforcement? Are there any spell casters involved in policing? Is spell casting banned?
Are their hounds or other types of creatures, perhaps magical, or other worldly used to track down fugitives?
What does the judicial system look like? Are you guilty merely by being caught, or are their judges and/or a trial? Do punishments consist of monetary fines, or cutting off body parts? Is slavery or indentured servitude part of the system?
Are there rules that “everybody” knows, unless you’re an outsider, but you are still expected to know? Is “The Law” chiseled into a monument, or kept in a large scroll somewhere?
Is exile an option? Is such exile at one’s own expense, or are you shipped off to a penal colony? The ancient Athenian version of exile was ostracism. So named because they wrote the person’s name on bits of broken pottery, an ostraka, plural ostrakon. The person was banished for ten years, and thus was “temporary”.
A city with a strong bent to lawfulness will tend to have a consistent way of handling crimes. Do racial issues come into play? Do humans and dwarves get along, for example?
Is the justice system fair for all who live there?
What about adventurers just passing through?
If this is a ruined city, what are the signs left behind of the justice system? Prisoners still on the rack? A pile of bones from the last hanging? Will undead of unjustly condemned prisoners lurk about these places?
In March, 2014 I published an article on districts or quarters of a city.