There is no ideal model of federalism - no template of best practices valid worldwide. Political, historical, social, and economic conditions shape federal institutions and processes, but these conditions vary by country. The idea behind Principles of Federalism is to draw up principles for the just, equitable, and effective governance of federations worldwide. These guidelines are intended to help framers of constitutions, government officials, members of civil society, and those who apply the law to reassess, reform, or rebuild political systems. They strive to identify the issues that must be considered regarding federalism, and they offer possible solutions. Principles of Federalism does not prescribe how specific problems are to be solved. The book describes what should be considered in policymaking in the hope that good practice will lead to an appropriate functional outcome. The guidelines are to be applied in governance, intended to help federalizing countries to establish - or federal countries to improve - their legal, institutional, and regulatory frameworks. Written by a Swiss working group towards the development of a universal instrument, the book's authors hope that the guidelines will be useful for all federations - existing, reforming, as well as emerging - around the world. As such, these guidelines should be understood as a work in progress, to be discussed, critiqued, and built upon.