NbS Triple Win Toolkit 3 Abstract Nature-based Solutions (NbS) are actions which enlist elements of nature or natural processes to address a particular problem, or suiteof problems, faced by society and which deliver multiple benefits in the form of public goods. This Toolkit offers guidance to achieve a ‘triple win’ to enhance biodiversity, address climate change, and reduce poverty, through NbS in the context of Official Development Assistance spend. The current state of knowledge was assessed from the literature and an analysis of 2,934 projects and 460 indicators was conducted. Principles are provided for the effective and efficient delivery of NbS, which are supported by case studies of NbS projects. Implementation Guidance builds on these Principles to present key considerations and possible tools to achieve the triple win. The Toolkit highlights the need to treat the enhancement of biodiversity as an explicit objective on par with addressing the impacts of climate change and reducing poverty;a review of Biodiversity Indicators provides recommendations to measure the impact of NbS interventions on biodiversity from the project to portfolio scale. Finally, the Economics and Financial Assessment presents a brief discussion of how benefit-cost ratios and value for money assessments vary for selected interventions. It also outlines barriers to private investment in NbS with possible models for leveraging private finance. Funded by Defra, this resource, as well as accompanying reportsand databases, were part of a project which ran from October 2020to May 2021. User Guide To make full use of this digital, interactive publication: Click on the titles in the top navigation bar to move between sections. Use the navigation bar or the ‘back’ button of your browser to returnto a previous section or page that you were reading. The Nature-based Solutions Triple Win Toolkit on page 11 is interactive, Click the orange arrow head next to each principle to read more. The Triple Win Toolkit: Implementation Guidance on page 22is interactive, please follow the instructions on this page. Glossary terms and references within the text are indicated with *hyperlinks*.