This article offers insights into how the design of innovations can enhance their “scalability”: the ability to adapt an innovation to effective usage in a wide variety of contexts, including settings where major conditions for success are absent or attenuated. We are implementing the River City MUVE curriculum, a technology-based innovation designed to enhance engagement and learning in middle school science, in a range of educational contexts. Based on our studies of these scaling up activities, we offer examples of design strategies for scalability and describe our plan to develop a “scalability index.”