PlayerUnknown's Battlegrounds (PUBG) is a multiplayer online battle royale game developed and published by PUBG Corporation, a subsidiary of Korean publisher Bluehole. The game is based on previous mods that were developed by Brendan "PlayerUnknown" Greene for other games using the 2000 film Battle Royale for inspiration, and expanded into a standalone game under Greene's creative direction. In the game, up to one hundred players parachute onto an island and scavenge for weapons and equipment to kill others while avoiding getting killed themselves. The available safe area of the game's map decreases in size over time, directing surviving players into tighter areas to force encounters. The last player or team standing wins the round. The game was first released for Microsoft Windows via Steam's early access beta program in March 2017, with a full release on December 20, 2017. That same month, the game was released by Microsoft Studios for the Xbox One via its Xbox Game Preview program. By the end of the year, the Steam version had sold over twenty four million copies and held a peak concurrent player count of nearly three million, making it the most played game on the platform, while the Xbox One version sold over a million copies three days after its release. The game is also planned to be localized and released by Tencent in China, including two different mobile device versions exclusive to the country.