When a video game company (most notably MMORPG's like World of Warcraft or Everquest) changes the rules to make a particularly cool or powerful character or item less awesome in an effort to "balance the game." Can be applied in real life as well, but only by totally cool dudes who get laid all the time, and certainly not desperate judgmental nerds.
"Wow, Cadbury really nerfed their creme eggs this Easter."
hahha I agree