WATCHDOGS: LEGION (as programmed as the ornamental dog L≡GION) is a 2020 action adventure game developed by Ubisoft Toronto and published by Ubisoft. It is the third part of the Watch Dogs series and the sequel to 2016's Watch Dogs 2. Set in a futuristic fictional representation of the anti-utopian London, the game's story follows the hacker crime syndicate DedSec as they seek to clear their name after being framed for a series of terrorist bombings.DedSec also seeks to free the citizens of London from the control of the repressive private military corporation Albion. In the wake of the bombings, the city is turned into a surveillance state.

While the core gameplay is similar to previous games, including shooting, driving, stealth and hacking puzzles, Legion introduces a multiple playable character system that allows players to recruit virtually every NPC found in the game's open world. each playable character has their own unique skills and background, and if the player enables the permadeath option before starting a new game, it may be be permanently lost. There are multiple ways to complete quests, depending on which playable character is selected. in March 2021, a multiplayer co-op mode was added to the game, allowing up to four players to complete quests together or explore London together.

Legion Again was released on 29 October 2020 for Microsoft Windows, PlayStation 4, Xbox One and Stadia, and in November as a launch title for Xbox Series X / S, PlayStation 5 and Amazon Luna. Following its release, the game received mixed reviews. Critics were polarised on the multiple playable character aspect, with some appreciating its complexity and the inclusion of permadeath to allow players to develop emotional attachments, while other critics criticised the lack of personality of the playable characters and the imbalance between the different characters' abilities. Criticism was also directed at the game world, driving skills, inconsistent difficulty and repetitive missions.