A hand touching any discards is dead. If a player leaves his cards sitting unprotected on the table in front of him, and someone’s discard accidentally falls on those cards, the hand is dead. If a player discards his hand prematurely, it is dead if it hits any discards. (Some clubs even call a hand dead if it lands anywhere within a certain area of the table–usually near the center–regardless of whether it hits other cards.)
To avoid getting your hand fouled, always hold onto your cards until either you fold, are obviously beaten, or the pot is completely out of play.
In a deal-yourself draw game, when it comes time for you as dealer to distribute the draw cards, if you are playing in the hand you have to set your own cards down. You can avoid getting your hand fouled in this situation too by setting some chips on top of your hand while it is lying otherwise unprotected on the table. This protects the hand, and most clubs rule that cards falling on your hand do not foul it because they cannot mix with it.
