Cyber based exercises are quickly becoming the defact-o way to test systems and networks in preparation for the next cyber based emergency. The concept of large scale cyber based emergencies has become a daily threat to those in the CERT profession, and to those which we protect. In order to ensure that we are prepared to handle the worst case scenario, industry and governments have taken to planning and participating in numerous cyber based exercises to support their ability to respond. However, bigger is not always better, and more is not always best. Having participated in and planned many cyber based exercises over the past 7 years, I will provide an experienced overview that will highlight the key areas and considerations that are essential to the development and deployment of well-rounded scenarios. Participants will leave the presentation with knowledge of what it takes to run an effective cyber exercise from both a domestic and an international viewpoint.