Paperclip a fruit or vegetable playing card, image side up, to the back of each participant's shirt collar.
Each playing card describes a technology, its potential benefits, and things to consider before deciding to use the technology.
The challenge was to draw one playing card at each of the five stations along the course.
British Dictionary definitions for playing card
one of a pack of 52 rectangular stiff cards, used for playing a variety of games, each card having one or more symbols of the same kind (diamonds, hearts, clubs, or spades) on the face, but an identical design on the reverse See also suit (sense 4)