The article examines the role of normative principles such as abuse of rights and good faith in international law with specific focus on investment law. It argues that abuse of rights and good faith provide an – albeit broad – framework to exclude some (few) types of abusive “exercises” of rights. Taking the concrete example of nationality planning in international investment law, it posits that important guidance may be derived especially from the concept of abuse of rights. This, however, is under the condition that the concept is subject to further criteria which guide its application to the specific case constellations at hand.