BG may refer to any of the following:
1. BG is shorthand used to describe a bad game. This lets other players in the game know that you thought the game was no fun, often because the game is off-balanced.
4. Short for battleground, BG is a place where people meet online to fight or battle.
5. BG is an acronym for the game Baulder's Gate.
6. BG is chat slang for big grin.