The effectiveness of hands-on learning isn’t new—for example, the apprenticeship system traces a rich history from ancient times to the present day. But well-designed game-based learning has several advantages over traditional experiential learning methods. It is cost-effective and low-risk (unlike, for example, safety training using live machinery). Perhaps even more important, there are significant learning advantages. Learners can re-enact a precise set of circumstances multiple times, exploring the consequences of different actions. In addition, well-designed games permit learning experiences that aren’t possible in real life—for example, “designing” a dolphin to find out how body size and fin position affect how far it can swim , or deliberately causing the biggest possible virtual explosion to understand why gas line disasters happen.