Many of the interventions and actions that fall under the categorisation of Nature-based Solutions (NbS) have been in practice by conservation science for decades – that history, along with their relatively recent collation under the umbrella term of NbS allow for a summary of lessons learned and refinement of common principles. Nine Principles were thus identified that together support the effective and efficient implementation of NbS. These Principles have been developed through a time-limited literature review and informed by a review of 378 NbS case studies (see Evidence Base chapter for further information). The Principles focus on opportunities and barriers to achieving the ‘triple win’ for biodiversity, climate, and people in countries eligible for Official Development Assistance (ODA). Each Principle may focus on delivery for one or a combination of the triple win objectives. However, it is important to recognise the potentially reinforcing relationship between biodiversity, climate, and people – delivering on one of these objectives can support the delivery of the others if designed intentionally and effectively. Enhancing biodiversity can provide health and livelihood benefits for local communities – thereby delivering on multiple dimensions of poverty reduction objectives – and support carbon sequestration and disaster risk-reduction – thereby delivering on climate change objectives. The Principlesare similarly reinforcing, and when taken together, the Principles guide the effective design and optimal delivery for all three objectives of the triple win. 10 Nature-based Solutions Triple Win Toolkit:Principles Nature-based Solutions Triple Win Toolkit:Principles Nature-based Solutions Triple Win Toolkit:Principles Nature-based Solutions Triple Win Toolkit:Principles Nature-based Solutions Triple Win Toolkit:Principles