The Borderlands video game franchise, created and developed by gearbox software and published by 2K, debuted in 2009 and since then has become one of the most successful franchises in 2K's stable. The franchise has sold more than 28 million copies globally to date across all three games in the series, including 15 million copies of Borderlands 2 – 2K's highest-selling game of all time. Through its unique blend of both FPS and RPG gaming elements The Borderlands franchise is widely considered to be the father of the FPS/RPG hybrid genre known as "shooter-looter" Though it is uncertain what caused krieg’s transformation into a psychotic killer, the game provides evidence hinting at an antithetical personality in the past. This is established by a fractured remnant of his Psyche, manifesting itself as an “inner voice” in his mind. It reveals that Krieg had previously engaged in Vault hunter-esque activities, such as aiding the needy, and getting paid with loot. The voice also seeks to control krieg’s lust for Murder By limiting his victims to those deserving punishment.