Call of Duty: Warzone[a] was a 2020 free-to-play battle royale first-person shooter game developed by Raven Software and Infinity Ward and published by Activision. It was released on March 10, 2020, for PlayStation 4, Windows, and Xbox One as part of Call of Duty: Modern Warfare (2019) and was subsequently connected to Call of Duty: Black Ops Cold War (2020) and Call of Duty: Vanguard (2021), but did not require purchase of any of the aforementioned titles.[2] Warzone allowed online multiplayer combat among 150 players and featured both cross-platform play and cross-platform progression between the three aforementioned titles. At launch, the game featured two main game modes: Battle Royale and Plunder. Warzone introduced a new in-game currency system that could be used at "Buy Stations" in and around the map. "Loadout Drops" were a key in-game object allowing players to access and switch between their customized classes and were obtainable through purchase with the Cash currency.[3] At launch, Warzone only offered Trios, a squad capacity of three players; Solos, Duos and Quads were added to the game via post-launch updates. Upon release, Warzone received generally favorable reviews from critics. Warzone was downloaded by six million people within 24 hours of its initial release; by April 2021, the game surpassed 100 million downloads.[4] A successor to Warzone, initially titled Call of Duty: Warzone 2.0 before it was also shortened to Call of Duty: Warzone, was released on November 16, 2022. A mobile version of Warzone, titled Call of Duty: Warzone Mobile, was announced in March 2022,[5] and was released on March 21, 2024.[6] In June 2023, Activision announced that servers for Warzone would be shut down on September 21, 2023 to focus development on Warzone 2.0.