Beyond the design space lies the terrain of the moderators. Their responsibility is to implement the design, make things happen and manage the consequences. An online role play without a moderator is unlikely to fulfil its learning objectives. This chapter introduces and explores the role of moderators – who may be the original designer, tutors working in a team-teaching context, or other educators selecting someone else’s design for use in their own context. It also locates the moderator role within the broader range of educational roles that may be more familiar to readers.