Enterprise Resource Planning (ERP) systems are commercial software packages that enable the integration of transactions-oriented data and business processes throughout an organization. Most of the world's largest organizations have already adopted an ERP system, and many mid-size organizations are turning to them as well. The implementation of an ERP system presents some major training challenges. Organizations devote significant portions of their implementation budgets to training and organizational change management interventions. Industry experts recommend that up to 20% of an implementation budget be devoted to adequately preparing managers and users. Studies also show a low return on investment for this type of training as it makes it difficult for knowledge workers to teach how to transfer what is learned in training to real-life jobs. Inadequate and ineffective training has the potential to seriously limit value realization. In that context, this paper presents ERPsim, a business simulation training approach developed at HEC Montreal in which the only interface between participants and the game is a real-life enterprise system (SAP). ERPsim recreates a realistic business environment that allows learners to develop IT competencies and skills in a setting that reflects the true complexity of the business world. This simulation approach is now used in over 100 universities and a dozen Fortune 1000 organizations. Yet, our experience shows that trainers need to approach simulation game training with a different attitude. This paper addresses the challenges faced by IT trainers in adapting to this innovative training approach. Based on our many training experiences, this paper provides instructors with guidelines to create a learning environment where learners have a reduced risk of making mistakes, to provide scaffolds that help learners build self confidence, and to help learners reflect on their mistakes, speculate on root causes, and intelligently design alternative solutions. Instructors trained with this approach report significant improvements in student evaluation, learner motivation, attendance, and engagement as well as increased learner competence with the technology. These guidelines can be transferred to a variety of other educational fields in which trainers are migrating towards a more active educational approach. (Contains 3 figures.)