Fluff

Fluff is gamer slang for the stories, lore, and in-character description of a system or setting; it is the opposite of crunch, which solely describes mechanical effects. For example, in Games Workshop's official fluff for Warhammer 40,000, the Space Marines are extremely hardcore superwarriors who regularly achieve kill-to-death ratios somewhere in the order of several thousand; crunch-wise, although tough, their statistics are not nearly as good as the fluff would suggest.

Powergamers typically ignore fluff to focus on crunch; however, the opposite extreme, a player who designs characters based solely on the fluff associated with their choices and ignores the crunch, can be just as annoying, as they have a tendency to produce characters that are very interesting and well fleshed out, but nevertheless cannot actually do anything useful within the game mechanics.