Oburato is a land, not yet succumbing to a darkness that threatens it. It's also a great place to play a D&D game.
There are five very powerful cities, each one a capital of a surrounding region.
These cities are connected by various major roadways. Each of the roadways are run by organized highwayman groups, each one vying for power.
Organized crime runs rampant throughout the land. Most "governments" are run via large syndicates, with the weaker syndicates being declared criminals, and the stronger ones retaining offical power. There are a few notably strong syndicates, however.
There are also various religious sects active in most cities.
Slavery is legal and lucrative in Ebul, Zelt, and Fantan. Slavery usually focuses on finding the weak and transporting them across the continent to a place the slave is completely bewildered. Slavery is not, however, a growing industry. The travel across land is incredibly dangerous, particularly with unwilling participants.
Slavers are typically powerful individuals, selling their slaves to other powerful individuals. Most slaves are also not common folk. The process of being transported is dangerous enough to filter out most of the typical people, such that those who chose "the life" in some way are all that's available - everyone else gets killed in the process. This makes the slaves themselves valuable, but also means that the buyer often is not in permanent possession, and several slaves quickly convert to indentured servitude. It all depends upon how powerful they become.
Oburato is the center of a large continent that is isolated by vast Oceans. The middle of the continent is some kind of dark, evil region, called the Kejahatan Lubang. Nobody knows what caused this region to appear. The Kejahatan Lubang appeared immediately centuries ago. When it appeared, the last Empire of the continent disappeared.
The time of the last Empire was a period where humanity reigned supreme. During this time, most growth centered around 5 major cities; these cities are the primary capitals of the modern era. The regular transit and communication was completely cut short when the Kejahatan Lubang appeared, however, as the only major waterways on the continent go through this region. In the time since, each of these cities grew into an independent region, each with it's own culture, and version of history.
In addition, the areas around the cities were unable to be effectively controlled. Since then, all manner of nature has taken over, except for a few regions kept maintained by small Eladrin and Elvish populations. There are a few isolated human settlements as well, but these are prone to attack. Only the most xenophobic populations seem to survive.