BioWare. (2010). Mass Effect 2 [Video game]. Electronic Arts; Microsoft Game Studios.

Mass Effect 2 is an action role-playing game developed by BioWare and released in 2010 for Windows and Xbox 360, with a subsequent PlayStation 3 release in 2011. As the second installment in the Mass Effect series, it continues the narrative of Commander Shepard, an elite human soldier tasked with assembling a diverse team to thwart the enigmatic Collectors, who are abducting human colonies in the Milky Way galaxy during the 22nd century.

The game enhances its predecessor's third-person shooter mechanics by introducing limited ammunition and regenerable health systems, emphasizing tactical combat. Players can import save files from the original Mass Effect, allowing prior decisions to influence the sequel's storyline, thereby creating a personalized narrative experience.

Gameplay involves real-time squad-based combat, where players can issue commands to team members, utilize a cover system, and deploy a variety of weapons and biotic powers. The game also features a morality system, with choices affecting character relationships and plot outcomes. In addition to the main storyline, numerous side missions, known as loyalty missions, provide depth to companion characters and can impact the game's ending.

Mass Effect 2 received critical acclaim for its presentation, character development, and refined combat mechanics, though some critics noted a simplification of role-playing elements compared to its predecessor. The game garnered multiple awards, including Game of the Year at the 14th Annual Interactive Achievement Awards and Best Game at the 7th British Academy Games Awards. It is frequently cited as one of the greatest video games of all time. A sequel, Mass Effect 3, was released in 2012, and in 2021, Mass Effect 2 was remastered as part of the Mass Effect Legendary Edition.