The book "Decision and Game Theory for Security" presents the refereed proceedings of the 4th International Conference on Decision and Game Theory for Security, GameSec 2013. This conference took place in November 2013 in Fort Worth, Texas, USA. The 15 revised full texts presented in this volume were carefully selected from a wide range of submissions and provide deep insights into analytical models based on game, information, communication, optimization, decision, and control theories. The focus is on the application of these theories to various security issues, highlighting the connection between theoretical models and real-world security problems. This creates an important feedback loop between theory and practice. Given the limited opportunities for researchers who wish to develop a deeper theoretical understanding of the underlying incentive and resource allocation issues in the field of security, GameSec is regarded as a significant forum of the highest standard that will continue to play an important role in the future.