Non-player character: A character in a game that is not controlled by a player, but instead by the game's artificial intelligence (AI). The term originated in tabletop role-playing games, where the gamemaster or referee controls the characters. In video games, NPCs can be neutral, followers, or adversaries, and their behavior can change depending on the player character's allegiance. For example, in Fallout 3, NPCs may spawn from portals while flags are being captured.