Innovation requires supportive innovation ecosystems. This book is about building innovation ecosystems and improving existing ones. These have the character of complex adaptive systems. Innovation ecosystems do not just happen; they need to be engineered. Cases and examples in the book of how to engineer innovation ecosystems illustrate widely applicable fundamentals. No previous knowledge of complexity is assumed. Innovation ecosystems are systems of people usually in organizations behaving as normal non-rational beings, making decisions, experiencing successes and failure, learning, and living. An innovation ecosystem is a complex system of connections and relationships among people and their environment. We call these Rainforests or complex adaptive systems. This book applies complex adaptive systems and Rainforest Thinking to building innovation ecosystems.Understanding such systems helps deliver economic and social benefits: entrepreneurship, new business opportunities, workforce utilization, exports, investment, quality of life, prosperity, and more in a holistic, positive manner; and, most importantly, a robust innovation culture. Strategic planning and planning strategies change when the environment is a mix of certainty and uncertainty, as in complex adaptive systems.