Legacy of Kain is a series of dark fantasy action-adventure video games primarily developed by Crystal Dynamics and formerly published by Eidos Interactive. The first title, Blood Omen: Legacy of Kain, was created by Silicon Knights in association with Crystal Dynamics, but, after a legal battle, Crystal Dynamics retained the rights to the game's intellectual property, and continued its story with four sequels. To date, five games comprise the series, all initially developed for video game consoles and later ported to Microsoft Windows. Focusing on the eponymous character of Kain, a vampire antihero, each title features action, exploration and puzzle-solving, with some role-playing game elements.

Legacy of Kain: Defiance is an action-adventure video game developed by Crystal Dynamics and published by Eidos Interactive for PlayStation 2, Xbox and Microsoft Windows. It is the fifth and final game in the Legacy of Kain series.