Simulations, along with games and scenario-based modules, are commonly accepted as an advanced type of e-learning. They increase learner involvement and engagement, which are both important in any learning environment. But if you dig deeper to understand how simulations actually enhance learning, it is rather difficult to find anything beyond superficial descriptions of what simulations are and how they might be implemented. In this session, we'll take what we know about human learning and cognition and reveal the specific instructional benefits of simulations. Based on that understanding, we'll outline six specific design requirements to ensure that educational simulations are also effective in creating lasting performance change. This session was recorded at the ATD 2019 TechKnowledge conference in West Palm Beach, Florida.