A major development of the law in the 1970s has been the extension of the principle of egalitarianism to the developmentally disabled, particularly the mentally retarded. In recent years numerous judicial decisions have overruled the practices of school districts that have excluded developmentally disabled children from educational programs. This monograph examines these cases and discusses their underlying legal principles, including the emerging "right to education" and the Fourteenth Amendment rights to equal protection and due process. The implications of the cases are explained for school authorities, who must identify, evaluate, and place handicapped children in appropriate educational programs. State constitutional and statutory provisions for educating the handicapped that help to explain the development of the legal aspects of educating the developmentally disabled are also examined. The appendix contains proposals for state legislative action to respond to the judicially established right to education mandates. (Author/MLF)