TRACS: Tool for Research on Adaptive Cognitive Strategies, is a new family of card games played with a special deck. Each card in the deck is a double-sided diagram, where the back gives a clue to the front. Compared to standard card games, this clue/truth structure makes TRACS more tractable to theoretical investigations in the lab and more typical of practical situations in the world. Here I present the design of the deck and discuss some research results.