The Fair and Equal Treatment principle forms the basis of investment protection standard that are often set out in International Investment Agreements and also often included in International Investment Arbitration. It aims at shielding multinational investors from unpredictable circumstances induced by their offshore investments in the host country. The definition and exact position from several opinions expressed the fair and equitable treatment as an independent convention standard, while others say it is a customary international law, and to the third party, it it a general principle of law.
The FET prinicple is mostly loosely defined by the treaties and contributed to broad explanations for investors by arbitral tribunals. While these explanations were controversial, there was consensus as to which values to form the fair and equitable quality of relationship between investors and the host States must be considered. They include good faith, legitimate expectation, due process and transparency. For Tribunals to judge a case-by-case review of the allegations from FET is not simple as the findings for either side are uncertain. In specific, in order to achieve legitimate public policy objectives, the Tribunals must align investor's interest with that of the Host Country (e.g., regarding environmental, social or economic development and public health).