Concentration (game) as an educational game. Any deck of playing cards may be used, although there are also commercial sets of cards with images. The rules given here are for a standard deck of 52 cards, which are normally laid face down in four rows of 13 cards each. The two jokers may be included for a total of six rows of nine cards each. Additional packs can be used for added interest. Standard rules need not be followed: the cards can be spread out anywhere, such as all around a room. In turn, each player chooses two cards and turns them
German playing cards 1865 by C.L. Wüst and carries many unique features. The kings were copied from French-suited patterns now found in the Netherlands and Portugal. The Obers were inspired by the Knights in Adler-Cego decks used in nearby Baden. Unters are journeymen. A younger type of this pattern, using different court designs also exist. In the present, the cards are sold as a doubled pack of 48 cards (24 unique cards duplicated). The duplicated cards (7, 10, U, O, K, A of each suit) are used to play Doppelkopf, Pinochle, and Gaigel. They used to be produced in 36 card packs (with