A new gaming tool and method of game play including an unconventional deck of playing-cards not employing symbolic relations, but rather employing actual relations between rectilinear geometric regions. The playing-cards preferably employ geometric interactions of reflection, complementarity, contrariety, and identity. Geometric card properties that further enhance game play include figure-ground reversibility, handedness, rotational transformation, and perpendicular association. Indexing indicia are optionally provided so that the user can easily visualize the rectilinear geometric regions on a playing card by looking at only the corner of the card.