This rapid literature review finds that lessons on the development and implementation of law and policy to protect and support internally displaced persons (IDPs) focus on the importance of political will and capacity to implement solutions.. IDPs may share needs with refugees and non-displaced citizens. Their needs may differ depending on whether they are displaced by conflict, violence, human rights abuses or disaster, whether a conflict is ongoing, whether they are living in urban or rural areas, among other factors. While the state holds responsibility, in situations such as conflict, national governments may be unable, or unwilling, to provide the necessary support to IDPs. This review focuses on lessons around the development and implementation of legal and policy frameworks to protect, support and find durable solutions for IDPs. here is overlap between international IDP instruments and national laws that may include instruments that protect IDPs as citizens. The papers surveyed for this review focus on the domestication of frameworks, as well as analysis of domestic instruments that may address IDP needs and may predate international IDP conventions. Much of the evidence takes instruments such as the UN Guiding Principles and AU Kampala Convention as best practice. This review focuses on lessons learned on the implementation of such frameworks that specify the need to protect IDPs and provide support for durable solutions to their displacement. However, it is important to note that in some cases, IDP situations have been dealt with effectively without reference to these frameworks or without IDP-specific laws. The available literature focuses on the development and implementation of IDP frameworks, as well as discussion of the efficacy of these frameworks in some cases. Summarising the reasons for failed implementation. This review attempts to include evidence on both ratification of IDP frameworks and implementation of policies, where possible. This review finds a number of broad reasons for lack of domestication and effective implementation. Broadly, these barriers to implementation can be characterised as either questions of political will or a lack of capacity. Lessons on implementing IDP frameworks, therefore, focus on likely drivers of political will, such as peace processes, development projects, external persuasion from other states, regional organisations or NGOs, or internal pressure from domestic institutions or organised citizens; methods to build capacity such training and funding. This review finds a number of broad reasons for successful domestication and effective implementation. They include: Political imperatives to protect, resettle or integrate IDPs; State capacity; The effect of institutional arrangements; The role of national civil; The role of regional bodies and international actors in spreading norms, expertise and building capacity; The need to engage with IDPs in order to shape appropriate policy.Foreign, Commonwealth and Development Office (FCDO)