Fluff
From Lexicanum
The term fluff is a euphemism common amongst certain groups of players for any the large amount of background information about the universes created by Games Workshop that is extraneous to the actual rules or playing of their games.
The term developed largely through the internet based community of players, as a shorter term to express the background and also because of its less formal connotations. The term 'fluff' is not used by Games Workshop themselves in reference to any such background, and is regarded by some as being some what offensive, as it implies that the background is not only ancillary, but actually unimportant and of little regard. Thus, as one of the major strengths of the games developed by Games Worshop is their engaging storylines, the term 'fluff' does not give background its due credit.
Nevertheless, because the term is not endorsed by the company it remains popular amongst gamers and continues to be used, as something about the game entirely owned by the gamers.
