In response to the twenty-first-century polycrisis engendered by global neoliberal capitalism and ongoing coloniality, we need to radically reimagine pluriversal alternatives of the social contract, as dynamic, inclusive, and regenerative processes that reshape our relationships with each other, with institutions, and with all living and non-living entities on our planet. This book offers the vision of new eco-social contracts to address root causes and for aligning governance, culture, and economy for a just society where people and the planet thrive. It blends theoretical insights with grounded examples from around the world to illustrate how such alternatives are already being envisioned, contested, and built. In this introductory chapter we first lay out the need for new eco-social contracts or eco-social alternatives to address the polycrisis. We then provide a brief history of the concept of the social contract, including its emergence during the Enlightenment in Europe but also the diversity of such contracts in Indigenous and other communities in the Global North and South such as the Sumak Kawsay and Ubuntu and then outline the core principles that we believe are necessary to animate eco-social transformations at various levels of governance. Finally, we provide an overview of the chapters that follow.