Coming from architecture, through computer science, pattern-based design spread into other disciplines and is nowadays recognized as a powerful way of capturing and reusing effective design practice. However, current pedagogical pattern approaches lack widespread adoption, both by users and authors, and are still limited to individual initiatives. This paper contributes to creating a shared understanding of what a pattern system is by defining the key terms. Moreover, the paper builds upon and extends a set of existing functional and non-functional requirements for pattern systems, adds structure to these requirements, and derives essential use cases following a goal-based approach for both pattern maintenance and pattern application. Finally, implications concerning the pedagogical use of pattern-based design are drawn, concluding that a stronger focus on the underlying (pedagogical) value system is required in order to make a pattern system a meaningful tool for effective educational design. (Contains 1 table and 3 figures.)