Since the original publication of Nudge more than a decade ago, the title has entered the vocabulary of businesspeople, policy makers, engaged citizens, and consumers everywhere. There are now more than 200 "nudge units" around the world, using the latest behavioral science research and sensible "choice architecture" to help us overcome the biases that lead to bad decisions and to nudge us toward the best choices for ourselves, our families, and our society. This completely updated edition offers a wealth of new insights for avowed fans of the book and newcomers alike—about COVID-19, diet, personal finance, retirement savings, credit card debt, home mortgages, medical care, organ donation, climate change, and "sludge" (paperwork and other nuisances we don't want, and that keep us from getting what we do want)—all while honoring one of the cardinal rules of nudging: make it fun!