APB: All Points Bulletin is set in San Paro, a persistent, online modern city which lives and breathes, filled with a population of civilians going about their daily lives. Joining the civilian population are opposing factions of players: Criminals and Enforcers, fighting for control and leaving their mark as they succeed or fail.
There are 3 Districts for San Paro. One is a Social District where players of both factions have a truce. They can socialise, customise and trade with each other. There are two Action Districts at release; one is the Waterfront, which is a marina and harbour area with a warehouse section, and the other is the Financial District, the financial heart of the city with skyscrapers, new building projects, residential areas, and even some slums.
Action districts are where users go to complete missions and use what they have created in the social districts. Users must pay for time spent in action districts but not for time spent in the social district. Within action districts, only specified players can be engaged by you as the user. You cannot attack anyone at any time. The game determines who is allowed to engage who.
There are rumors of more districts in future releases of APB, and still rumors floating of a chaos district where everyone can attack anyone at any time (excluding enforcers versus enforcers.) As well as a district that enforcers can only engage a criminal if they witness a crime.