Similarly, some games that are placed in the card game genre involve a board. Many games that are not generally placed in the family of card games do in fact use cards for some aspect of their gameplay. 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. Countless card games exist, including families of related games (such as poker). 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.