Defiance is a science fiction-themed persistent world massively multiplayer online third-person shooter developed by Trion Worlds. Defiance takes place on a terraformed Earth several decades into the future. It is a tie-in to the Syfy show of the same name. The game was released on April 2, 2013, for Microsoft Windows, PlayStation 3 and Xbox 360. It was also released on Steam. The game went free-to-play on 4 June 2014 for PC, 14 August 2014 for PS3 and 18 November 2014 for Xbox 360.
Defiance has dynamic events called "Arkfalls", similar to dynamic world events pioneered by Tabula Rasa and Trion's previous game Rift (video game). Arkfalls are massive chunks of alien ships containing valuable technology that fall from space, attracting Human and Votan scavengers and ark hunters.