The standard 52-card deck of French-suited playing cards is the most common pack of playing cards used today. A key feature of most playing card decks is their double-sided design: the backs of all cards are identical, helping to conceal each card's identity during play, while the faces are unique and display a suit and rank used in game mechanics. In English-speaking countries, the 52-card French-suited deck is the predominant traditional pack used for card games, although other types of playing card decks, such as tarot and specialty packs, are also available. Worldwide, the most common design for French-suited cards is the English pattern, while several other regional patterns, including the Belgian–Genoese pattern, are widely used in parts of Europe, North Africa, the Middle East, and the Balkans. In addition, many countries continue to use traditional decks with different suit systems, such as German-, Italian-, Spanish-, and Swiss-suited cards. Standard deck sizes also vary by region, with 36-, 40-, 48-, and 52-card packs commonly used depending on local playing card traditions.