Mass Effect 2 is an action role-playing game developed by BioWare and published by Electronic Arts. The game is a sequel to Mass Effect, and the second game of the series (Mass Effect (series)). The game was released on PC (Personal computer) and Xbox 360 in North America, Europe and India on January 26, 2010, Australia on January 28, and New Zealand on January 29.

After the events of the original game, Commander Shepard (Characters of Mass Effect#Commander Shepard) is killed in an ambush by a mysterious alien species called the Collectors. Shepard is revived two years after the attack by an enigmatic organization called Cerberus, and is tasked with finding out more about the Collectors and why they are abducting entire human colonies. Shepard must build a team in order to accomplish what seems to be a suicide mission. Many elements and locations from Mass Effect return, in addition to ones new to the series.

A critical and commercial success, Mass Effect 2 had shipped over two million copies worldwide within a week of release, and has also received highly favorable reviews. It is ranked third on the Xbox 360 according to GameRankings, and is, overall, the fourteenth best reviewed game of all time. The game holds several perfect scores and has an average of 94 and 96 for the PC and Xbox 360 on Metacritic respectively .