This Federal Emergency Management Agency (FEMA) document is intended to explain the principles of seismic design for those without a technical background in engineering and seismology. The primary intended audience is that of architects and includes practicing architects, architectural students, and faculty in architectural schools who teach structures and seismic design. Currently no single publication exists that provides up-to-date information necessary to architects, presented in a form that is attractive, readable, and intelligible to a non-specialist audience. This revised publication will fill that gap. The present publication consists of a series of chapters that provide the foundation for an understanding of seismic design, each authored by an expert in the field. The authors were given freedom to decide the scope of their chapters; and thus this publication represents expert opinion rather than consensus.This is a privately authored news service and educational publication of Progressive Management.