This book is for funders, academics, and practitioners responsible for assessing social and development impact in complex systems. Traditional evaluation approaches often miss how change unfolds across time, relationships, and systems, focusing instead on isolated outputs that distort understanding of real impact. This book responds by applying systems thinking and equity lenses to impact evaluation. It provides practical tools and reflective approaches to surface hidden patterns, power dynamics, and unintended effects, enabling a deeper and more accurate understanding of change in complex environments.