Abstract
The incorporation of indeterminate legal concepts into administrative regulations and their relation to discretion portrays topics of great relevance and consideration for Administrative Law. This
study seeks to systematize doctrinal discussion and analyze the inclusion of these concepts into legislation. In general, we will address the legal norm of administrative discretion, the doctrine of indeterminate legal concepts and the evolution of Costa Rican administrative litigation jurisprudence regarding this matter. This issue is greatly relevant for legal operators, both for the law makers in the procedure of establishing the law, and for judges of contentious procedures in their role as comptrollers of the legality of administrative actions.