Noun
(role-playing games, video games) A character in a role-playing game or computer game whose actions are not controlled by a player.
(Internet slang, derogatory) An individual who does not think for themselves nor makes their own decisions.
Source: en.wiktionary.orgThere used to be an old joke in role-playing circles-it isn't funny these days-that there were only a thousand real people in the UK-everybody else was a non-player character. Now it's pretty much the reverse. Charles Stross