The Witcher 2: Assassins of Kings is an action role-playing hack and slash video game developed by CD Projekt RED for Microsoft Windows, Xbox 360, OS X, and Linux. The game was released for Microsoft Windows on 17 May 2011, for Xbox 360 on 17 April 2012, for OS X on 18 October 2012, and for Linux on 22 May 2014. It is a sequel to the 2007 video game The Witcher. Like its predecessor, the game is based on The Witcher series of fantasy novels by Polish author Andrzej Sapkowski. The player directs the actions of Geralt of Rivia, a monster hunter known as a Witcher. The fantasy world in which his adventures take place owes much to Polish history and Slavic mythology. The game was a critical and commercial success, selling more than 1.7 million units for the PC and Xbox 360 by May 2012. The third installment in the story, The Witcher 3: Wild Hunt, was released in May 2015.