I claim the ornamental design for a set of chess playing cards, as shown and described.
FIG. 1 is a front elevational view of a chess card set, showing my new design;
FIG. 2 is a left-side elevational view of one of the cards, the other cards having identical left-side elevational views and omitted for clarity of illustration, the right-side elevational view of all cards being a mirror image thereof; and,
FIG. 3 is a top plan view of FIG. 2, the bottom plan view of all cards being a mirror image thereof.
The broken lines showing text in FIG. 1 depict environmental matter and form no part of the claimed design. The rear side of each card in the set forms no part of the claimed design.