The method selected for the design of structures not only can affect their seismic vulnerability but also can affect their construction cost. For the design of steel structures, two distinct methods have been introduced by existing codes, namely allowable stress design (ASD) and load resistant factor design (LRFD). In this book, the ASD and LRFD methods which are widely employed by designed engineers for steel structures are compared in terms of their vulnerability against seismic actions and their economical aspect.