When a Swiss or U.S. firm invests abroad, especially in emerging economies, what protection does it enjoy under international law? Is it shielded, for example, against expropriation, discriminatory regulation or abuse by foreign courts? This course examines the public international law of investment protection both in customary international law and treaties, in particular bilateral investment treaties (BITs), free trade agreements (including NAFTA, CETA and TPP) and the Energy Charter Treaty. It provides an in-depth analysis of procedures for investor-state dispute settlement under arbitral facilities such as ICSID and analyses the exponentially growing case law in the field. The course devotes attention also to the environmental and social issues surrounding international legal protection of foreign investment and efforts to regulate the rights and obligations of multinational corporations. This is an overview course on the subject matter. No prior knowledge is required. Students in disciplines other than law are welcome.