Welcome to the Risk Calculus, a  podcast from the UC Berkeley Risk and Security Lab [https://brsl.berkeley.edu/], where we explore pressing questions at the intersection of technology and national security. In our first five-part mini-series, Professor Andrew Reddie takes a deep dive into an old way of thinking about risks that is being applied in new ways both here at the lab and beyond—wargaming. The renaissance of wargaming in academic and policy circles, along with a growing public interest in this approach to risk analysis, make it an ideal time to examine the method's past, present, and future. What is a wargame? Who designs and plays these games? And how should we interpret what they tell us? To unpack these questions, Andrew is joined by guests working at the cutting edge of research and practice.