My brother is trying to make "darf" an all-purpose word (similar to the way the Smurfs use "smurf") in gaming, usually in the context of something bad ("I totally darfed that skill check," "That minion darfed his attack," etc.).
This comes from playing the board game Atlantic Star, whose rules are in German (though we have an English translation downloaded from the internet). Every player has a card in front of them that describes the various actions available to them on each turn, one of which is clearing away the cards that are currently available to purchase, getting new cards in their place. The rules card explains in German that "Man darf..." do this, which means "one may..."
My brother decided he wanted to clear away the cards, so he said he'd "darf" them. We were amused by this and decided to keep using it in other games.