Risk/need analysis and treatment of mentally disordered offenders (MDOs) take place in constrained clinical settings, but violence has to be considered in a context where both social and cultural factors are of significance. One way to improve treatment and risk/need analysis of MDOs could be to develop simulation systems where users interact with video-based scenarios. The objective of this study was to develop and pilot test a simulation system to be used as a tool to study MDOs and possibly also to play a part in their rehabilitation. Collaboration between simulation and forensic psychiatry experts and a professional film team was set up. A simulation system called 'Reactions on Display' (RoD) was developed and a pilot study with eight patients and 13 staff members was carried out. Results from the study showed that RoD's interface and design were well received by patients and staff. Participants indicated that they found the video sequences realistic and the system enjoyable to use. The pilot study of RoD was positive, but further research should study possible clinical outcomes of the system. However, we believe that RoD could provide an advance in treatment and risk/need analysis of MDOs.