Ruff-and-slough (pronounced ruff-and-sluff) is a play in contract bridge. A defender trying to defeat a suit contract leads a card in a suit in which both dummy and declarer are void; and both dummy and declarer have at least one trump.
This play gives declarer the option of discarding a losing card from one hand while playing a trump from the other, usually garnering an undeserved trick in the process. Thus the ruff-and-slough is a play generally to be avoided by the defenders; except in rare cases where declarer has no side suit loser to discard.