Virtual worlds and immersive simulations are designed to create a compelling, ­collaborative, and participatory experience for the user, and often contain a variety of features not possible in the real world to enhance users´ engagement and learning. Over the past several years, an increasing number of immersive virtual environment experiences have become available for both educational and entertainment purposes. Participants in entertainment experiences now number hundreds of millions, yet adoption in educational settings has been limited thus far. In this chapter, we review examples of virtual worlds and immersive simulations that are designed, or adapted, to support situated learning experiences, analyze their use for a variety of educational purposes, explore theoretical foundations, identify learning affordances and limitations, and examine instructional design considerations.