Caveat Emptor is vaguely real-estate themed, with the board depicting a 7x7 array of lots, divided into sections of different sizes and shapes. Each lot is also marked with a Roman numeral from I-V. Players have sets of cards with the same numbers - on each round every player selects a card to be auctioned, but these are all shuffled together so no one knows exactly what will be available. The gimmicks are that the winner of each auction can choose any like-numbered lot to own, and that the winning bid goes to the person who played the card, but no one knows who that is until the auctions are over.
Each lot has an intrinsic value based on the size of the section it is in, the bigger the section the more valuable. However, a player can double or triple the value of his or her lots in a section by owning a majority or all of them, which is of course easier to do in a small section. When a section is full the lot values are put into accounts for each player - these accounts earn interest every round, and the players are allowed to add a certain amount of cash to them as well. The interest can be significant but withdrawing money from the account before the end of the game is somewhat painful.