Only those who will risk going too far can possibly find out how far one can go.?T. S. EliotWe all take risks. Individually, we may decide to marry or just leave the house. Such decisions are often made subjectively without any quantitative analysis. Communities take risks when they decide not to build protection against flooding. Nations take risks when they invest in other countries or go to war. The human race take risk with its acceptance of the balance of nuclear power or global warming as a policy for peace. The acceptance of risk by individuals is often very different from the acceptance of the same type of risk by groups.This book discusses different aspects of risk together with some choices and presents examples to enlighten the reader. The author has written books on topics such as earthquakes hazard assessment and risk analysis.