Duo is a fast, light card game inspired by classic Crazy Eights, but with a twist of colors, numbers and symbols. Each deck contains cards that combine one of four colors, one of four numbers and one of four symbols, yielding 64 distinct combos. At the start each player draws seven cards and two discard piles are opened from the deck. The goal is to shed all your cards before the opponents. To play, you place a card on the chosen pile if at least two of the three attributes match the top card. You may stack as many cards as you like, provided they all follow this rule and go onto the same pile. If you cannot make a move, you draw a card and pass the turn. The deck also includes wild cards that match any attribute and semi‑wild cards that match only one attribute, adding extra strategic flexibility. Each player starts with 15 points; when someone goes out, they subtract from their score the total number of cards remaining in other players' hands. The first to reach zero wins. A typical game lasts about 20 minutes, supports 2‑6 players and has a low complexity rating (≈1.7/5), making it perfect for quick, thought‑provoking duels. While the rules are simple, tracking three attributes at once creates a mental challenge that appeals to families and friends alike who enjoy short, twist‑filled rounds. Duo earned the Mensa Select award in 1995, guaranteeing that despite its easy learning curve, it still offers a satisfying level of strategy for quick thinkers.