In this chapter, the basic specifications for design of flight control systems have been outlined. It should be pointed out that historically, flight vehicle HQ guidelines evolved as a basis for the design of a new aircraft with desir able dynamic characteristics using only low authority stability augmentation systems. With the modern full authority high-gain fly-by-wire flight control systems, most of these specifications can easily be achieved. However, other design problems associated with such high-gain/high-bandwidth feedback systems, namely (i) stability margins, (ii) interaction of structural modes with rigid body dynamics and (iii) actuator rate saturation during large-amplitude manoeuvres in the presence of severe atmospheric turbulence, etc. take centre stage in the control law design process. Brief specifications/guidelines to meet these practical control system design requirements have also been outlined. The guidelines detailed in this chapter will be used for the design studies in Chapters 9-11. Additional useful flight control design practices have also been well documented in Reference 17.