Ravnica. A plane spanning city. Home of ten legendary guilds which control aspects of the city, and therefore the world, ranging from entertainment to law keeping to information gathering. In recent years the clashes of these guilds have risen and fallen, yet the Guildpact keeping peace has stayed in place. Until recently, where a planeswalker named Jace Beleren has become a living embodiment of this peace. So far, Ravnica and the Guildpact have been kept safe. Of course, this does not keep the cities ten guilds from their inevitable clashes, be they discreet or open to public knowledge.
Not that all are tied into these ten guilds. Many of Ravnicas citizens are guildless, favoring to go about their business without the need to pay homage to one guild or another. For many, this is an active choice. For others, it is simply because they have not gotten their shot to join a guild. What better way to gain the honor of being accepted into a guild than adventuring, doing glory for yourself and your city?