 The only exception is when you have put down all your other cards in combinations.When it is time to discard and the only card left in your hand is a Joker, you are allowed to discard it, thus ending the game.Thus, drawing a Joker from the stock, especially towards the end of the round, may be a serious inconvenience if no escaleras have been put down or if all the escaleras on the table already contain Jokers.