The galaxy is vast, and humanity is only just finding its place. In a galaxy populated by various races competing for political power, humanity has only just entered the political sphere and is rising to power. Commander Shepard is a member of the Spectre Corps, a cross-species force that aims to bring peace to a galaxy in constant political turmoil.

Mass Effect is the beginning of a grandiose space saga in which players take on the role of Commander Shepard and combat enemy forces attempting to disrupt the galactic peace, while also building relationships with team members, and uncovering dangerous secrets.