Our main focus in this and the next chapter is the application of Cooperative Game Theory (CGT) models to international water resource issues. In this chapter we will justify the use of CGT in water resource problems, and in particular, in international conflict-cooperation cases. The chapter reviews several important CGT concepts and demonstrates their use and calculation. After reading this chapter you will have a good grasp of basic CGT concepts and be able to apply them at both conceptual and empirical levels to simple cases.