I can't really tell you. That guy is "Gordon Freeman", the main character in the Half-Life game serie. According to the following article, it comes from the "La

I can't really tell you. That guy is "Gordon Freeman", the main character in the Half-Life game serie. According to the following article, it comes from the "Lambda complex" where he's working on in the first serie, which is in also made-up for the game: http://half-life.wikia.com/wiki/Lambda_logo http://half-life.wikia.com/wiki/Lambda_logo