In this chapter we will explain how to obtain massive deformations, i. E. Scalar potentials and cosmological constants from dimensional reduction. We start by reviewing some aspects of standard kaluza-klein reduction. Then we will introduce a mechanism to generate masses in lower dimensions, called scherk-schwarz dimensional reduction, which will be used in chapter 4 to construct gauged and massive supergravities in ten and nine dimensions. For reviews on the subject of dimensional reduction see