

Progress in co-op earns the player rewards in Mass Effect 3: Galaxy at War that can be used to influence the outcome of Mass Effect 3's single-player mode.

In this mode, up to four players can join together online and customize characters to fight on the front lines of the galaxy-wide war against the Reapers, as well as Cerberus, Geth and Collector forces. Cooperative multiplayer is a game mode that is featured in Mass Effect 3, and marks the debut of multiplayer in the Mass Effect series.
