The rest of the cards are placed face down to form the stock. Then the players may look at their cards. The dealer then turns up the top card of the stock to begin play. If you draw more cards, then you have to keep these cards in your hand. Valid cards are those that match the suit or number of the top face-up card.
Jacks are also valid cards since they are wild.
Doing so would result in a misplay penalty. 3 - If a player plays a 3, the next player has to play a 3 or draw 3 cards. If he players a 3, then the player after him must play a 3 or draw 6 cards, etc. 6 - Previous player draws 2 cards. When a 9 is played, the drawing of cards start with the person who was scheduled to play after the player of the 9 and go in the direction of play, finally to the player who is before the player of the 9.