

In the campaign, the player controls a vigilante named Aiden Pearce, who possesses the singular ability to hack into various electronic devices tied to the city's central operating system, the CTOS, through his Smartphone, via an application dubbed the " Profiler". In the game's universe, the Northeast blackout of 2003 was found to be caused by a hacker, prompting the development of CTOS. The city's overarching network controls almost every piece of technology in the city banks, security cameras, traffic lights, communication hubs, and even key data on the city's residents and activities have been complied into the system and can be used for various purposes. In this version of Chicago, everyone and everything is connected.

The game is set in a contemporary fictionalized version of Chicago, Illinois, which is one of many cities to feature a supercomputer known as CT OS ( Cen tral Operating System). The storyline of Watch Dogs explores the impact of technology within our society bringing to the forefront the concept of information warfare, data being interconnected, and the world's increasing use of technology - questioning who exactly runs the computers they depend on.
