Investor–state dispute settlement (ISDS), or an investment court system (ICS), is a set of rules through which states can be sued by foreign investors for certain state actions affecting the foreign direct investments (FDI) of that investor. This most often takes the form of international arbitration between the foreign investor and the state. As of June 2024, over US$113 billion has been paid by states to investors under ISDS, the vast majority of the money going to fossil fuel interests.