A card game is any game using playing cards as the primary device with which the game is played, be they traditional or game-specific. Countless card games exist, including families of related games (such as poker). A small number of card games played with traditional decks have formally standardized rules, but most are folk games whose rules vary by region, culture, and person.
Many games that are not generally placed in the family of card games do in fact use cards for some aspect of their gameplay. Similarly, some games that are placed in the card game genre involve a board. The distinction is that the gameplay of a card game primarily depends on the use of the cards by players (the board is simply a guide for scorekeeping or for card placement), while board games (the principal non-card game genre to use cards) generally focus on the players’ positions on the board, and use the cards for some secondary purpose. Given the association of card games and gambling, the pope, Benedict XIV, banned card games on October 17th, 1750.
Playing cards, set of cards that are numbered or illustrated (or both) and are used for playing games, for education, for divination, and for conjuring.
Traditionally, Western playing cards are made of rectangular layers of paper or thin cardboard pasted together to form a flat, semirigid material. They are uniform in shape and size and small enough for several to be held together in one hand, frequently fanned out so that the identifying marks on each card can be seen. One side of each card—its front, or face—is marked so as to render it identifiable and distinguishable from its fellows, while the back, or reverse, is either blank or bears a pattern common to all. The corners are usually slightly rounded to prevent fraying. In the second half of the 20th century, it became common to add a plastic coating to resist wear and even to produce all-plastic cards.
Card games typically exploit the fact that each player can identify only the cards he holds, not those of his opponents. This same characteristic also applies to dominoes and to the gaming tiles of mah-jongg. In fact, British domino players often call dominoes “cards,” mah-jongg may itself be the ancestor of card games of the rummy family, and in China there is no clear-cut dividing line between cards and dominoes, the latter being made of lacquered paper.