This book provides a unified practically-oriented treatment to many constrained control paradigms. To this end, recently proposed control strategies are unified in a generalized framework to deal with different kinds of constraints. The resulting control strategies are based on reference conditioning ideas, implemented by means of supervisory loops which employ discontinuous actions. Although design simplicity is a book priority, the use of well established variable structure systems theory and sliding mode related concepts for theoretical analysis make the book also rigorous and self-contained. The book aims at providing solutions which can be added to pre-existent control designs, and that allow using conventional control tools for the main loop design. Switching signals are always confined to the low-power side of the systems, so that the implementation of the control schemes results extremely easy, both analogously or digitally.