Disasters create overwhelming demands to affected communities and pose unique problems that complicate efforts of orchestrating the response. It is in such environments of uncertainty, operational friction, time-constraints and the need for interagency coordination that disaster and crisis managers are required to develop incident plans to address multiple demands. Based on observations from 50 disaster exercises, we have identified twenty critical points in incident planning, that is, those incident planning activities which are most challenging for emergency managers, are poorly implemented or otherwise constitute an area for improvement. The most challenging components of the incident planning process were information gathering from the field, running estimates of the situation, response-generated demands, resource capabilities and mobilization time, course of action development and analysis, and decision-making under uncertainty. In addition, this study identified three good practices in incident planning. First, the process is iterative and planners revisit several steps in a back-and-forth fashion. Second, both rational and intuitive decision-making processes are likely to be used during the course of any one incident, based on the time available for planning. Third, better plans are produced when flexibility is built into courses of action to address expected developments of situation or when decision-making is decentralized.