This book reviews the background, methods and examples of how to embed 3d simulations in online education. How to build 3D simulations in virtual worlds that engage, immerse and grab student attention while uplifting student learning is the focus of the book. The aim of the book is to provide the reader with many ideas about embedded 3d simulations in courses or training exercises with specific attention to innovation and ideas. Examples are provided in Unity 3D along with working code examples that can be used to assist new simulation designers. Topics include: tools, review of alternative methods, scripting, affordances for simulation, assessment and evaluation, audio and chatbots.