“One of the paradoxes of game design is that the creativity of play is made possible by play’s opposite, which are rules,” he says. “Rules are in essence constraints, but games don’t feel that way. Basketball is an amazing example of this. When the rules are activated, what follows is fluid, unpredictable magic. If you read the rules, you would never guess that’s what emerges.” But Naismith’s original rules resulted in clumsy, low scoring affairs. Where does the magic come in? Zimmerman gives his classes an assignment where they try to improve tic-tac-toe. He asks them to write out the game’s existing rules on the whiteboard and then has them brainstorm gameplay adjustments that will ideally create a totally new experience. “My favorite variation was when the students altered just one rule: If you get three in a row, you lose. It was a small tweak, but it completely changed everything. I just thought it was so elegant.” A game becomes exponentially more fun once its players learn to get creative within its boundaries. It’s less about following the rules and more about filling in the gaps that exist between them. Zimmerman uses poker as an example. “There’s nothing in the rules about bluffing,” he says. “There’s not a rule that says you can lie if you don’t have a good hand. It’s intrinsic to the system. Bluffing is an emergent property that appears out of the negative space of the rules.” For a game designer, this is everything. It’s how a snow-day diversion evolves into a global phenomenon. “I’m getting chills just talking about it,” he says. — 19: 255-267