D&D - Guildmasters' Guide to Ravnica

Gildes that are so old that it can no longer be remembered, occupy the throne of power in the endless maze that is known as the city of Ravnica. Market squares and shady streets are the playground of crime gangs, scientific institutions, tenders and military units who all want to assert their own influence, money and power.
You deposit into a world where every guild has its own identity and function. Various varieties, creatures and subcultures give you access to this world. Can you keep your place within it? Or do you lose control of your piece of domain in a world full of war and intrigue?
To play in this setting you have the Dungeon Master's Guide and the Monster Manual needed.