In all that we do, we try to predict the future, at least in the short term. We consider what impact a decision or intervention will have on the system - whether it be a company, project, family, friends, etc. Most of the time, we do not think about this consciously but decide intuitively. Strategy, production, and project plans are typical anticipations of the future. However, as the world becomes more complex, meaning there are more dependencies, it becomes increasingly difficult to anticipate the system's reaction. As a result, plans are becoming less effective. Peter Addor has been contemplating this issue for a long time and is trying to figure out how managers and other decision-makers can still lead despite complexity and uncertainty. How should they behave? How should they decide? This book seeks to provide answers to these questions.