Mr. Riehle began as a child designing active games to play with his friends in elementary school. These games involved throwing things at each other to simulate fireballs or rules for character advancement while playing lazer tag. They generally involved hit points- a concept he'd borrowed from the PC game, Wizardry. He went on to create rules for combining various games with Pokemon- first Chess and Tarot cards, later Advanced Dungeons and Dragons Second Edition.
In his adult life, Joe returned to creating active games for children to play in after school programs. In an effort to include educational topics in the children's play, the games attempted to simulate such things as Heisenberg's uncertainty principle, predatory food webs, and the colonization of Central America. More recently, he creates less physically demanding games when he's not otherwise engaged.