Overwatch is a team-based first-person shooter developed by Blizzard Entertainment and released for Microsoft Windows, PlayStation 4, and Xbox One in May 2016. The game, while having several different play modes, generally features two teams of six players each, selecting pre-made heroes from the game's roster, to either attack or defend various objective points on the game's maps. The game supports casual game modes as well as ranked competitive play. Since release, Overwatch has been both critically and financially successful, with a player base of 35 million players as of October 2017.
The development of Overwatch started in the fallout following Blizzard's decision to cancel continued development of the massively multiplayer online role-playing game Titan around 2013. After most of the rest of the team was transferred to other projects, the remaining team members, led by director Jeff Kaplan, came up with the concept of a team-based shooter that borrowed elements from other online shooters like Team Fortress 2 and multiplayer online battle arenas. Many of Overwatch's early assets were borrowed from Titan to obtain a proof-of-concept to greenlight further development. The consequences of Titan's cancellation also led into creating a narrative of an optimistic near-future setting for the game, taking place some decades after the formation of the peacekeeping Overwatch team, created in response to a robotic uprising known as the Omnic War.
Since release, the Overwatch developments continue to produce more content, released free for all, for the title, including new hero characters, maps, game modes, seasonal events, customization options for the characters, and external media such as digital comics and shorts to help support the narrative and character's backstories. Blizzard has also made changes to make Overwatch more compatible for professional eSports, including support for its Overwatch League that started its first season in January 2018.