A stacked set of playing cards are supported to expose an information
bearing portion bearing a first machine-readable indicia and an
information bearing portion bearing a second machine-readable indicia,
such that each of the first and second machine-readable indicia from a
number of cards are read by at least one reader. The second
machine-readable indicia may provide redundancy, or may be related to the
first machine-readable indicia to allow the authentication of the playing
card.