There is vigorous debate about reforms to address the balance between investor protection and the right to regulate in the over 3000 existing investment treaties. This paper first notes the growing trend to analyse particular treaty rules rather than treaties as a whole and the importance of comparative analysis of balancing under other regimes. It then outlines issues in four areas: (i) the types of regulation potentially at issue in investment treaty claims by covered investors; (ii) the types and levels of investor protection; (iii) the degree of impact of treaties on regulation; and (iv) the processes and institutions that may be involved in balancing interests in investor protection and the right to regulate. While the paper recognises that dispute resolution institutions have a significant impact on the balance and the right to regulate, it focuses primarily on substantive issues in light of other ongoing work on dispute settlement.