In Watch Dogs Legion, you get to build a resistance from virtually anyone you see as you hack, infiltrate, and fight to take back a near-future London that is facing its downfall. Welcome to the Resistance.
The game is set within an open world, fictionalised representation of London, which will encompass notable landmarks, boroughs, and cultural styles of the city. The game's setting takes place within a London that has become a surveillance state. Personal liberties have been vastly limited, and citizens are constantly monitored in their activities by Albion, a private security company that acts as the city's law enforcement. The player will have the ability to navigate the city either by foot, using vehicles, or fast-travelling via the city's Underground stations. Unlike the previous games in the series which focused on the use of a single protagonist to drive the story's narrative, Legion features the ability to control multiple characters within the game's setting. Each of these characters can be recruited through a unique mission, though this depends on their standing with DedSec; for example, a character who the hacker group helps out will be in favour of aiding them when asked and completing their recruitment mission, whereas a character whose family member was accidentally killed by a DedSec member will not tolerate the group and likely refuse to join.
Once a character is recruited into the player's roster, they are assigned to one of three classes: combat, stealth or hacking. Each class features its own set of tools and ability upgrades when a character levels up from completing missions and activities. Each character also has their own background which dictates a special skill or trait they have. For example, a recruited character may be more skilled with drones and thus can do more damage with them, while another is an "adrenaline junkie" who deals more damage but at the possible risk of dying at any random moment. All characters in the game recruited into the player's roster have their own personal lives when not being controlled, can be fully customised with various clothing options, and can wield a mixture of lethal and non-lethal weapons.
Although the player can recruit a large roster of characters to control, each can be permanently lost during the course of a playthrough. Characters risk the possibility of being killed either while conducting operations for DedSec against other groups or against local law enforcement; in such cases where the currently controlled character is critically injured, players can choose to either make them surrender to their opponents and allow them to be rescued by another character, or attempt to resist and lose their pursuers at the risk of being killed in action and being permanently removed from the player's roster of playable characters, thus forcing the player to switch to another character.
Players can also join a team of up to four players in cooperative gameplay, sharing progression between single-player and multiplayer modes.