Some of the cards feature a black or white ball. These are voting tokens, used to elect people to secret societies. Hence the phrase "to blackball" someone. Each person is given both a white and a black card. White means 'yes', black 'no'. Each person chooses the card corresponding to their vote, and places it face down in the middle. The cards are then shuffled before being turned over and counted. After the vote each person puts their remaining card in the center and these two are shuffled before being put back in the deck (so there is never any record of who voted which way).