The show is to premiere next spring in connection with the start of a new massive multiplayer online game.
"Defiance" stars Grant Bowler, Julie Benz, Stephanie Leonidas, Tony Curran, Jaime Murray, Graham Greene, Mia Kirshner and Fionnula Flanagan.
"Set in the near future, 'Defiance' introduces a completely transformed planet Earth, inhabited by the human and alien survivors of a universal war," Syfy said in a synopsis. "Forced to cohabitate, the disparate group struggles to build a new society among the devastation. The dramatic tapestry of the series and the intense action of the game will exist in a single universe where their respective narratives will inform one another and evolve together into one overall story."