Mass Effect is an action role-playing game developed by BioWare for Xbox 360 and Microsoft Windows. The Xbox 360 edition was released worldwide in November 2007. The PC edition was released on May 28, 2008, published by Electronic Arts. The game takes place in the year 2183, with the player assuming the role of an elite human soldier named Commander Shepard, set out to explore the Galaxy on his ship, the SSV Normandy.

In addition to plans for two sequels to complete a trilogy, BioWare plans to release episodic content via Xbox Live to fill in the story between each game, though these episodes are not essential for understanding the main plot line. The first of these downloadable content packages was released on March 10, 2008 for the Xbox 360 only. A PC edition of this additional content is due for release in summer 2008.