Contributed by James Banks
There are two versions, a solitaire (usually 13-cards in hand and row) or a multiplayer (4-5 cards in hand and row).
Dealer shuffles to all players' satisfaction and places the proper number of cards face up in a row (the "cookies") in front of each player. Hands of the proper number are dealt face down for however many players are playing - the number of cards in each hand should be the same as the number of cards in each row. The players take whichever face down pile they desire as their hand, the dealer getting last pick. Remaining cards are placed in a face down stack within reach of the players from which cards are to be drawn when necessary.
Play begins with someone other than the dealer. The first action is to select a cookie monster. This is a card of the player's choice, taken from their hand and placed sideways face up at the left end of the cookies. The cookie monster can (and must) eat any card directly to the right of it having the same suit and a higher rank. This continues until it runs into something it cannot eat.
Now, at all times, the number of cards in the player's hand must equal the number of cookies he has remaining, no more, no less. When cookies are eaten, cards must be discarded to make up for the loss. When cookie monsters are played, a card must be drawn to compensate.
Any time cards are discarded for any reason, the player's turn ends. However, a monster is allowed to eat all the cookies it can before the player has to discard cards. The next player then plays.
Cards can be traded (but not given) to other players, sight unseen.
A player can discard any number of cards from his hand, ending his turn, but giving him the opportunity to draw new, hopefully better ones.
Cards may be swapped between the hand and the row of cookies if the cards have the same suit or the same rank (a la "Crazy Eights").
The player may swap his cookie monster for another card of the same suit or rank. However, the old monster must be discarded and the player's turn ends as soon as the new monster has eaten any cookies it can.
If your cookie monster eats all your cookies, you win. Yippee. Whoever has the most remaining cookies at that point becomes the loserest of losers. The loserest of losers must do some kind of silly thing (impersonating Sesame Street puppets, drinking large quantities of water, asking a stranger for a hug, etc.)
If you draw all the cards in the pile, the game ends and everyone must do a silly thing together (everyone lost), but the loserest of losers must do an additional silly thing.
Solitaire: deal 13 cards initially, play as normal (although your turn doesn't end).
In many well-loved decks, a certain card will become "lucky" from violent games (such as Slam [a game similar to Slapjack in which pairs of cards and deuces are slapped]), it's luckiness evident by the fold-marks on its back. If such a card is declared by another player to be in your hand, you lose the ability to discard (remedy this by swapping the lucky card with a cookie and hoping you can work with that card in your cookie row).