Who Stole the Cookie?

In Who Stole the Cookie? you need to figure out who has both of your cookies because just one is never enough!

To set up, shuffle 2-3 cookie cards with 6-15 crumb cards depending on the number of players, then place two cards in the center of the table and deal two cards to each player, with everyone being able to peek at only one of their cards. On a turn, a player can:

 Peek: Look at any one face-down card.
 Switch: Switch the position of any two cards.
 Shuffle: Have someone shuffle the two cards in front of you, then look at one of them.
 Declare: Declare you know where two cookies are, choosing a card that you have or a card in the center of the table only if you can choose both of them. Secretly look at those cards, winning if you're correct and getting removed from the game if you're not. Find the cookies and you win!