This chapter reviews previous studies on game theoretical analyses on electoral promises and explains the main implications and contributions of this book. The main purpose of this book is to provide a theoretical framework that analyzes the following two characteristics of campaign promises based on the political competition model. First, this book builds a model with partially binding platforms, which supposes that although a candidate can choose any policy, there is a cost if they betray their electoral promises. The policy to be implemented is affected by, but may be different from, the platform because this cost of betrayal increases with the degree of betrayal. Second, this book also discusses political ambiguity which means that candidates make vague promises in electoral competitions by allowing themselves to choose a lottery instead of a single policy. This book shows that these models can explain many aspects of real elections that cannot be predicted by previous frameworks. These findings confirm the importance of analyzing electoral promises explicitly using game theory.