30 Carats

30 Carat players start with the exact same items: a colored screen to hide their goods, five gemstones of each color in play, and five gold nuggets, but they won't stay the same for long! After all, each player is dealt a secret rating card, ranging from +30 to -30, and gemstones that match their screen color will have this value at the end of the game. (Gold nuggets are always worth +10 points.) Do you need to sell or buy your initial holdings? And how do you figure out the value of everything else?

Each player also starts the game with three transaction cards. Each transaction lists a minimum bid that a vendor must make on their turn, for example, at least two gems of their own color or one gem of their own color and two gems of a neighbor's color.

The game lasts three rounds, labeled morning, noon, and night. In each round, each player will be the vendor once. The player chooses one of their transaction cards, then places a bid on the table that at least matches the required minimum bid. If the transaction is tagged "simultaneous", each of the other players must simultaneously reveal an offer of their own, which must include at least one stone/nugget and must not match the seller's offer; if the transaction is "in succession", each opponent reveals his offer in a clockwise direction. After viewing all the offers, the seller trades goods with an opponent or pays 2-4 pips to the bank to place their offer in the bank's bag (along with their pips), then takes that number of items out of the bag. (The bank's bag starts with the same items as each player.)

In games with at least four players, the vendor can pay 2-4 gold nuggets to the bank to see the secret rating card that has any opponent.

Once each player has been a seller three times, the game ends and each player reveals their rating cards. Players then count up their scores, and the player with the highest total wins, with gold nuggets in hand to break the tie.