The Last of Us for introducing a complex gay character to its to its post-apocalyptic narrative.
"[Bill is] an unstable loner in the town of Lincoln with a talent for fixing things. Through dialogue and backstory, the player learns that Bill once had a partner named Frank who he loved, but the plague drove them apart and led Frank to a bitter end," notes GLAAD in its list featuring characters form other mediums. "Both helpful and contentious, Bill is as deeply flawed but wholly unique a gay character found in any storytelling medium this year."
Other instances of LGBT characters in 2013 included a plot line in Gone Home, a playable character in State of Decay and ... well, there is a debate to be had about Animal Crossing: New Leaf's Gracie the Giraffe – a male character in the Japanese game, who is designated female everywhere else.