After an ante from all players, the dealer gives five cards, face down, to each player and puts an extra hand ("widow") of five cards in the middle of the table. He must deal to each player in turn around to the left, one card at a time, then to the widow, then to himself last. Each player has the option of exchanging his hand for the widow, or keeping his hand as it is. If a player takes up the widow, his original five cards are placed face up on the table and become the new widow. Each player in turn has the option of taking up one card or all of the new widow and replacing it with cards from his hand. If a player wishes to play the original hand, he signals by knocking on the table, but he may not draw and knock at the same time.
The process of exchanging cards continues around the table until some player knocks. A knock means that this player will show the present hand as soon as it is his turn, so that each player has only one more chance to exchange cards. No player may draw if he has knocked. A player may knock before the widow is exposed, if desired.
If no one takes the widow until it comes around to the dealer, the dealer must either take up the widow or turn it face up on the table. Even if the dealer knocks, and does not take up the widow, he must spread it on the table for each player to see and draw once more. A player may pass at any turn - that is, decline either to exchange or to knock; however, he may not pass at two turns in a row. Having passed on the previous round, he must either exchange or knock.
After the knock and the final round of draws, all hands are shown, and the highest takes the pot. The lowest pays a "forfeit," or penalty in an amount of chips agreed upon beforehand. Some players prefer to have a round of betting before the showdown.