Mining agreements (MAs) often reflect governments' political aspirations. To allow their deals to conclude with minimum risk and maximum benefit, mining investors must know and understand the motivating factors of the governments of applicable countries, and their consequences. The form and substance of MAs vary considerably and may be adapted to suit a country's particular legal and socioeconomic framework and the peculiarities of the sector of the mining industry concerned. Developing countries are now relentlessly competing for investment funds, offering attractive conditions for transnational mining companies. In developed countries, on the other hand, the desires to protect the environment and to guarantee or restore natives' rights have caused a downward shift in investment priorities. This text: sets out the various forms an MA can take; examines the key role played by national political will in MA negotiation through an analysis of MA evolution in four host countries - Australia, Chile, Indonesia and Papua New Guinea, all of which are particularly attractive countries for foreign mineral investment; explores the main trends in the evolution of MA content over the past 30 years - including the dramatic increase in environmental requirements, the growing concern over natives' rights, and the decrease in economic rent and equity shares; traces the trends' origin in the HCs' political will with the TMCs' need for stability; and explains how to write an MA that will stand the test of time. These features position this work to provide participants in the running industry - transnational and mining companies, national governments, and international organizations - with bargaining solutions for the mining agreements of the future and to heighten their awareness of actual present and foreseeable changes in the political, social and investment climate.