12 Days is a card game based on the traditional Christmas carol, the Twelve Days of Christmas. The majority of the cards in the game are the gifts that you would expect: 1 partridge in a pear tree, 2 turtle doves…, all the way up to 12 drummers drumming. Each gift card is numbered – with the number equal to the number of those gifts in the deck. There are also two non-traditional gift cards, Santa Claus and Mrs. Claus, and each of these cards is given the number zero.
The game is played over 12 rounds – each one representing one of the days of Christmas. There is a second small deck of 12 day cards, numbered 1 to 12, which are used one in each round in ascending order. Players are dealt a hand of 12 cards from the deck of 80 cards, and the remainder is placed on the table as a draw deck.