Halo 5: Guardians

Halo 5: Guardians is a 2015 first-person shooter game developed by 343 Industries and published by Microsoft Studios for the Xbox One. Set in the 26th century, the plot follows two fireteams of human supersoldiers: Blue Team, led by Master Chief, and Fireteam Osiris, led by Spartan Locke. When Blue Team goes absent without leave to track down the artificial intelligence construct Cortana, Master Chief's loyalty is called into question and Fireteam Osiris is sent to retrieve him. Players fight enemies with an armament of different weaponry and vehicles in story-based and multiplayer modes, including a larger-format 24-person mode called Warzone.

343 Industries started to plan Halo 5 shortly after the release of its predecessor, Halo 4. In late 2012, the team set goals for the game, including larger campaign and multiplayer areas. Different departments worked collaboratively to build off each others' work for the campaign mode. The move to the Xbox One console allowed the development of the Warzone mode alongside traditional multiplayer modes, part of 343 Industries' focus on allowing for different play styles. Its game engine dynamically adjusts its resolution to maintain a frame rate of 60 frames per second; the focus on performance meant that offline capabilities or local networking were not included.

Microsoft announced the game at E3 2013. The game sold five million units within three months and is the seventh-best selling game for the Xbox One. Upon release, Halo 5 received positive reviews from critics, with praise directed at its gameplay, visuals, level design and multiplayer modes. However, the game's single-player campaign met divided responses, with criticism directed at its story, writing, and ending. A sequel, Halo Infinite, was released on December 8, 2021.