In the face of panic and life-threatening situations in a hospital emergency room (ER), doctors must rely on well-defined procedures to assess the situation and respond appropriately. Because decisions to act must not only be timely, but also ingrained and swift, practice and experience in a wide range of situations is essential. This paper outlines the analysis, design and prototype development phases of a Web-based role-play scenario in which the students of surgery can add to their repertoire of experience in ER medicine. Examples of existing online case study and role-play activities for clinical and ER training were studied. The instructional design decisions took into consideration the desirable attributes of these examples, but more importantly, addressed their shortcomings. The prototype features an interface that enables the student to make many decisions at one time while proceeding to stabilize and diagnose the patient. After completing the procedure, the student's report is posted to an online discussion site for peer analysis and critique. The development of a future prototype is also discussed. (Author)