The Asian Infrastructure Investment Bank (AIIB) opened in 2016, as a US$100 billion multilateral development bank (MDB) financing public and private infrastructure projects for Asia. AIIB's investments in its first ten years totalled more than US$60 billion. Among its 110 approved members are countries in Asia and Oceania, Europe, Africa, and the Americas. In addition to highlighting key innovations from AIIB's first ten years in operation, the second edition of A Comparative Guide to the Asian Infrastructure Investment Bank examines AIIB through the lens of its Charter, focusing on its mandate, investment operations, membership, finance, governance framework and decision-making, and institutional setup. Why these elements matter for MDBs is explained, followed by analysis of the AIIB Charter text, and comparison with its predecessors. The book begins with two chapters new to the second edition and largely new to the literature. The first delves into the legal origins of the 1945 World Bank Charter, finding its roots in the Bank for International Settlements in 1930 and a bank never established, the Inter-American Bank of 1940. The second chapter traces the adaptation of the World Bank Charter through other MDB charters, in the process telling the story of AIIB's founding. Uniquely, this book takes apart the AIIB Charter for the general reader and the specialist, from the perspective of the Chief Counsel who put it together. It's an inside look at how this new international organization went from concept to reality, and a handy legal guide to MDBs, newly updated in 2025.