Ravnica is a plane covered in a large city, also referred to as Ravnica. It takes its flavor from that of Eastern Europe. The technological level of Ravnica is a little strange. There is electricity, running water, and all sorts of things but the knowledge and means to make use of such things is concentrated within the Izzet League. The izzet do provide some civil engineering, but for the most part people live in pre-industrial revolution fashion. A person could have a sink instead of a well, but they'd also have candles or oil lamps instead of electric lighting in their kitchen. Money in the setting is known as zibs and zinos, let's say zibs are worth more. Honestly, there's so much to the setting that I couldn't possibly explain it all myself HOWEVER if there are fundamental things about Ravnica you need to know-ask, and I'll do my best to answer. I also highly recommend digging through this wiki for information as you need/want.

The Guilds of Ravnica.

The Azorius Senate is the legislative and judicial body of Ravnican bureaucracy. They establish laws and regulations and function as judges, and legislators. Guild members of t he azorious can be deeply, oppressively bureaucratic and order-obsessed or merely want the stability that the azorious provide without the perils of other guilds such as the boros or orzhov, or the cultural baggage of the selesnya.

The Boros Legion is a standing army that protects the Guildpact and contains the League of Wojek, the official peacekeepers of the City of Ravnica. Though they are often brutal in stamping out what they consider criminal activity, they do provide the most consistent and direct intervention on the behalf of citizens when such situations arise.

House Dimir is no longer a hidden guild. As the general populace now knows of their existence, it was required that they adopt a public face, so the lower ranking members serve as couriers, investigators, reporters, and archivists. It also provides illegal but necessary services, assassination, theft, smuggling, etc and this is where there true power lies.

The Cult of Rakdos, considered a necessary evil by some, is composed of thrill-killers who provide the heavy labor force of the plane as well as providing entertainment of all kinds to the denizens of Ravnica.

The Golgari Swarm manages food production and organic waste disposal, a vital task-and are composed of people and races that have a history of being maligned and mistreated. Many golgari live underground, where they stay out of necessity, want, or fear of persecution.

The Gruul Clans have fallen from their former glory as the keepers of Ravnica’s wilds and now are a loose affiliation of berserker clans. They exist mostly on the untamed and abandoned outskirts of ravnica, resentful of the other guilds for a variety of reasons.

The Izzet League is responsible for civil engineering works and new magical developments. Mad science, but mostly the lightning, and explosions, and teleporting kind.

The Orzhov Syndicate regulates trade and banking, among other fields, notably including serving as lawyers. The guild is one that emphasizes ambition, and ruthlessness in the pursuit of wealth, power, and longevity-at any cost. Many members of the orzhov are in fact debtors who's cunning and ambition betrayed them, now magically and legally bound to serve the guild even after they have died, as a ghost. The guild possess extreme social, political, financial, and magical might, though the greatest of this is concentrated among the highest ranking guild members.

The Selesnya Conclave promotes the strongest religion and its ledev guards patrol the rural areas. On their face the selesnya are peace loving and express a desire for harmony, and this is true. At there worst they are highly xenophobic and arrogant to those outside their guild. The selesnya has the largest amount of combat capable members of any guild short of the Boros Legion.

The Simic Combine provides medical assistance and performs biological research. Like the Izzet league they are highly intellectual and prone to experimentation though their pursuits are often in the realm of magically enabled biological tinkering. Blending or creating species, producing or modifying biomes, etc.