Introduction: Critical Decision Method (CDM) is an interview technique known for eliciting tacit knowledge. The interview discusses the cognitive tasks and difficulties around a challenging incident faced by an expert. The output is a collection of compelling stories with plenty of learning points. In the military, wargaming is a simulated exercise to plan and trial tactics, techniques and procedures. Setting up the wargaming exercise and instructions requires meticulous planning and in-depth knowledge of the task. Method: The study interviewed 27 experienced officers and elicited 40 stories with 155 decision points. Decision points from 7 stories were selected and translated into training instructions and learning points for a standalone scenario-based training software. Results and Discussion: Through the data collection, design, and implementation, the team identified the key parameters needed in eliciting expert’s knowledge for instructional design pertaining to warfare. This paper describes how the CDM interview can be shaped to support instructional design for wargaming

Keywords: Critical decision method, Instructional design, Cognitive Ergonomics, Modelling, Simulation.