Mass Effect is an action role-playing video game developed by BioWare and originally released for the Xbox 360 video game console in 2007. It is the first game of the Mass Effect series, taking place within the Milky Way galaxy in the year 2183. The player assumes the role of Commander Shepard, an elite human soldier who must stop a rogue agent from opening a portal for a highly advanced machine race of synthetic-organic starships that are believed to eradicate all organic civilization every 50,000 years. The gameplay requires the player to explore a galaxy map to find and complete quests. Most of the game's main quests are combat missions, while secondary quests generally involve the player gathering items or interacting with non-player characters.
Planned as the first chapter of a trilogy from the very beginning, Mass Effect was developed over the course of three and a half years and uses the Unreal Engine 3 as a groundwork. It was designed so that the player would assume the role of a central character that could make important decisions and impact the story of the game in numerous ways. The combat was designed to offer the tactics and customization of a role-playing game, but through a simpler and real-time third-person shooter interface. In 2008 and 2009, two downloadable content packs that introduced new missions to the base game were released.
Mass Effect received critical acclaim from video game publications and sold more than one and a half million copies as of January 2008. Critics praised the game's interactive storytelling and cinematic design, but criticized its unbalanced combat mechanics and poor artificial intelligence. The game received several year-end awards, including Best RPG at the 2007 Spike Video Game Awards and Roleplaying Game of the Year at the 2008 D.I.C.E. Awards. Mass Effect was ported to the Microsoft Windows and PlayStation 3 platforms in 2008 and 2012, respectively. A sequel, Mass Effect 2, was released in 2010.