Setis a very popular card game with strong mathematical structure. In this paper,
we describe “anti-Set”, a variation on
Setin which we reverse the objective of the
game by trying to avoid drawing “sets”. In anti-Set, two players take turns selecting
cards from the
Setdeck into their hands. The first player to hold a
set loses the
game.
By examining the geometric structure behind
Set, we determine a winning strategy
for the first player. We extend this winning strategy to all nontrivial affine geometries
over
,
of which
Setis only one example. Thus we find a winning strategy for an infinite
class of games and prove this winning strategy in geometric terms. We also describe a
strategy for the second player which allows her to lengthen the game. This strategy
demonstrates a connection between strategies in anti-Setand maximal caps in affine
geometries.