Book excerpt: This book focuses on the topic of competency-based scenario design as it relates to Intelligent Tutoring Systems (ITSs). The current book is the ninth in a series of books that examine key topics in ITSs. The chapters in this book specifically relate the work presented to applications for the Generalized Intelligent Framework for Tutoring (GIFT) (Sottilare, Brawner, Goldberg, & Holden, 2012; Sottilare, Brawner, Sinatra, & Johnston, 2017). GIFT is an open-source, domain independent, service-oriented, modular architecture for ITSs. GIFT has specifically been designed to allow for reusability of the GIFT architecture, GIFT tools, and instructional content materials. Further, GIFT has been designed with the goals of reducing the amount of time necessary to author ITSs, and reducing the skill level required for the authoring process. GIFT can be used to create ITSs that can be distributed both locally on a computer and virtually in the Cloud. In addition to creating ITSs, GIFT can be used to examine instructional outcomes, and conduct research. The topic of this book, Competency-Based Scenario Design is highly relevant to the development of ITSs. Scenarios are information-rich task/problem contexts that are closely aligned with real-world situations that professionals face in their jobs. The tasks/problems exhibit ecological validity rather than stripped-down abstract simplifications. Developers of ITSs and other adaptive instructional systems need to have principled guidance on how to design these scenarios. An example scenario may be a close match to a particular situation in the past, but not be representative of a large range of situations that professionals experience in their job. An example scenario may be very realistic, but not provide reliable and valid assessments of the learners' performance to guide assessments (summative, formative, or stealth). Research teams that build high quality scenarios need to include expertise in the targeted profession, assessment, learning science, and computer science. The current book brings together experts on ITSs to discuss their work as it applies to Competency-Based Scenario Design. We believe that this book can be used as a resource for those who have an interest in developing Scenarios for ITSs, and who want to learn more about how to do so.