Deus Ex: Mankind Divided is a direct continuation of Adam Jensen's journey, taking place two years after the world-altering ending of Deus Ex: Human Revolution. The canonical ending of the previous game is a mix of the different endings where whatever Jensen's plan was to save humanity was unsuccessful, and mankind has become engulfed in a civil war over the ethics of human augmentation, resulting in the persecution of augmented individuals. The conflict reached a boiling point when two factions - Interpol, a private military company that Jensen belongs to that is bent on exterminating augmented humans, and an organized resistance - targeted one another. Jensen also moonlights as an informant for "The Juggernaut Collective", a covert operation whose interests conflict with Interpol. The story will setup the world present in Deus Ex, which takes place 23 years later.
Gameplay-wise, Mankind Divided places a strong emphasis on player choice, allowing a totally-binary approach to either "full-stealth" or "full-combat" at any point in the game. Notably, boss fights can be defeated without directly engaging in combat. Missions are selectable by talking to characters in the game's hubs, and their objectives can conflict with the interests of both parties Jensen serves. There are over twice as many available augmentations than present in Human Revolution, and weapons can be fully customized on-the-fly.
AI opponents no longer splinter off by themselves, but move as a unit, and many are outfitted with augmentations. Gunplay was a specific focus during development, as most players reported enjoying the game more when played stealthily. Environments are able to respond dynamically to combat. There is no multiplayer component planned.
Details were initially reserved for reveal in the April 2015 edition of Game Informer, but were leaked on April 7th 2015, one day early. The existence of the title was confirmed later that day by Eidos Montreal via Twitter, and by Game Informer via YouTube. Moreover, Square Enix prepared an official announcement during a multi-day Twitch livestream, where a man was depicted as being trapped in a prison. Viewers could affect the stream in multiple ways, such as voting between two choices at specific times or changing the cameras. While the announcement and reveal trailer leaked before the end of the stream, it continued as planned.