This document discusses the roles of game designers in predicting and improvising. Game designers must analyze player behavior through scientific methods like hypotheses and testing while also being adaptable to changes. Designers are encouraged to notice more details, use diverse tools and materials, get out of their thinking and just act, treat everything as potential resources, and combine simple elements to create living game worlds. The document was presented at the annual Game Happens festival in Italy to discuss game design, interaction design, and virtual reality.