This chapter discusses various principles that may limit the amount of compensation that an investor may recover. Causation is examined, focusing particularly on legal causation. The effects of the investor's actions on compensation through contributory negligence and the obligation to mitigate losses are also discussed. The chapter touches upon a State's counterclaims, particularly the issue of jurisdiction over counterclaims in investment treaty arbitration. The state of necessity defence, in both customary international law and under investment treaties, is examined with its effect on the amount of compensation due; with particular attention to the cases arising from the Argentine financial crisis in 2000–02. Other included principles which affect compensation are the issues of burden of proof and the prohibition of double counting. Finally, the chapter examines the application of equity in awarding compensation.