There has been much recent interest in the concept of rewilding as a tool for nature conservation, but also confusion over the idea, which has in turn limited its utility. We outline a unified definition and a series of ten guiding principles for rewilding, drawing on a global advisory group of rewilding experts. These were developed through a survey of 59 rewilding pioneers, a summary of key organisations’ rewilding visions, and academic/practitioner workshops involving over 100 participants from around the world. The resulting principles are intended to clarify the concept of rewilding and to improve its effectiveness as a tool to achieve global conservation targets including actions of the UN Decade on Ecosystem Restoration and post‐2020 Global Biodiversity Framework. As such we note the potential contribution of other related conservation approaches such as the IUCN CEM NbS programme. The guiding principles developed here state implicitly that rewilding sits upon a continuum of scale, connectivity, and level of human influence, and aims to restore ecosystem structure and functions to achieve a self‐sustaining autonomous nature. We suggest that differences in rewilding perspectives lie largely in the extent to which this is seen as achievable, and ultimately, in those interventions which are necessary, feasible or acceptable. An understanding of the contextual setting of rewilding projects is often the key to success, and careful site‐specific interpretations will be most successful at achieving the aims of rewilding. Article impact statement: Rewilding is on a continuum of scale, connectivity, and human influence and aims to restore ecosystems to achieve self‐sustaining nature. This article is protected by copyright. All rights reserved

Cost-effective zones for the expansion of global terrestrial protected areas are identified.