"Gordon Freeman is a fictional character, the main protagonist of the Half-Life video game series. He is a theoretical physicist (Ph.D. from MIT) who finds himself thrust into a battle for survival against both alien and human forces. Throughout the series, Gordon must prevail in hostile situations despite overwhelming odds, often without backup. As a means of immersing the player in the role, the character never speaks, and there are no cut-scenes or mission briefings - all action is viewed through Gordon's eyes, with the player retaining control of Gordon's actions at nearly all times.
The character is introduced as a theoretical physicist working at the fictional Black Mesa Research Facility and involved in an experiment which accidentally opens an interdimensional portal, releasing confused, hostile beings into the complex. In the first Half-Life, the player, as Gordon Freeman, fights through the facility alongside fellow employees, engaging the aliens as well as a black ops military unit sent in to contain the situation and silence any surviving witnesses. In its sequel, Half-Life 2, Gordon is introduced to a dystopian world years after the Black Mesa incident, along with an interdimensional imperial force known as the Combine that took advantage of the interdimensional portals and has established itself as the ruling force on Earth. Gordon joins the human resistance fighters and aids them in their struggle against their oppressors."
Source: Wikipedia, "Gordon_Freeman", available under the CC-BY-SA License.