This chapter discusses seismic performance objectives and illustrates how limits on peak displacement and ductility demands constrain the properties of acceptable oscillators. Descriptions of the degree of damage to structural components, nonstructural components, and building contents at various shaking intensities have been articulated in greater detail, in parallel to the increase in precision in the specification of seismic hazard, the computation of structural demands, and the characterization of component capacities. The robust analytical tools that are available can be used to achieve more uniform performance over the large range of buildings presently designed based on prescriptive requirements and linear elastic analysis, on the one hand, avoiding the cost of needless conservatism, and on the other, reducing the risk of unacceptably poor performance. Performance-based design refers to the explicit consideration of building performance at several different seismic hazard levels during the design process.