  EvenQuads is a new card game that is a generalization of the SET game, where
each card is characterized by three attributes, each taking four possible
values. Four cards form a quad when, for each attribute, the values are the
same, all different, or half and half. Given $\ell$ cards from the deck of
EvenQuads, we can build an error-correcting linear binary code of length $\ell$
and Hamming distance 4. The quads correspond to codewords of weight 4.
Error-correcting codes help us calculate the possible number of quads when
given up to 8 cards. We also estimate the number of cards that do not contain
quads for decks of different sizes. In addition, we discuss properties of
error-correcting codes built on semimagic, magic, and strongly magic quad
squares.
