In the prototype kids' kit, players come up with a sequence of chemical reactions they want to make. They then punch holes corresponding to their sequence into paper cards. The cards are pre-loaded with chemicals. To get their reactions to go, players put the cards through the hand-cranked card reader, which releases chemicals one drop at a time at every punched hole. In a statement, the professor who created the system, Manu Prakash of Stanford University, said he envisions kids trading successful reaction cards like baseball cards.