The document discusses the origins and development of the blue circle mechanic in PlayerUnknown's Battlegrounds (PUBG). It quotes the game's developer saying he was inspired by the squares used in the Japanese film Battle Royale but found circles easier to implement in his game. He started with circles that moved across the island in the Arma 2 mod. The blue circle mechanic and PUBG were referenced in an Indian news story in September 2017.