Christopher Bingham and I report on our research about the simple rules – fast, flexible heuristics are most effective in times of change. We initially studied simple rules in the context of entrepreneurs capturing new opportunities. We found that those entrepreneurs who developed simple rules performed better, capturing opportunities far more effectively than those that did not. But simple rules aren’t only important for entrepreneurs and innovators, they are also an important tool in adapting to change. To see this in the context of the Covid-19 crisis, recall that the Americans were uncoordinated in the initial weeks of the pandemic. Many things were done, often haphazardly, and rarely based on lessons based on experience. South Koreans, in contrast, selected the right critical processes and centrally coordinated simple rules for them, namely, test, trace and isolate. The rules were then implemented throughout the country.