The card game SET is a game of pattern recognition. In this talk, we discuss the interesting mathematics behind a deck of SET cards. We will discuss how SET can be used to visualize the finite affine geometries of order 3. We also present recent results and discuss what Terence Tao has described as "perhaps [his] favourite open question." This talk should be accessible to undergraduates and graduate students of all ages. The only background required is algebra on the level of Math 100 and combinatorics on the level of an algebraist. (Joint work with M. Follett, K. Kalail, E. McMahon, and C. Pelland.)