Storytelling is a powerful tool for understanding. This casebook presents seventy dilemma-based narrative cases, providing language teachers with a thorough overview of key topics in language education. The cases cover a broad range of language teaching and learning concerns relevant to the development of pre- and in-service language teachers. They include narratives of language teachers, learners, teacher educators, researchers, administrators, and other professionals working in a variety of educational settings, such as schools, universities, private language institutions, and informal contexts, and in multilingual contexts around the world. Cases illustrate theoretical principles and concepts current in the field, in the form of moral or practical dilemmas that require resolving by readers. Case components include discussion questions, related research topics with suggested methods for carrying out research, and reading resources. A facilitator guide provides suggestions for conducting classroom and online discussions, creating case-based assignments for assessment, and mentoring teacher research.