Players in 30 Carats start with exactly the 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 receives a secret valuation card, ranging from +30 to -30, and the gemstones matching the color of his screen will have this value at the end of the game. (Gold nuggets are always +10 points.) Do you need to sell or buy your initial holdings? And how do you find out the value of everything else?!
Each player also starts the game with three transaction cards. Each transaction lists a minimum offer that a seller must make on his turn, e.g., at least two gems of his own color or one gem of his color and two gems of a neighbor's color.
The game lasts three rounds, labeled morning, midday and night. In each round, each player will be the seller once. The player chooses one of his transaction cards, then places an offer onto the table that at least matches the minimum offer required.