Developing teams capable of completing projects in extreme situations is becoming a major challenge for a growing number of organizations. The notion of collective competence is increasingly being seen as a vital precondition for the success of project teams, particularly in extreme environments. However, we still know little about the ingredients of this collective competence. To partially fill this gap, we make use of the insights offered by the very particular world of the French Special Forces, which have been operating successfully for several decades in extreme environments. Based on an in-depth qualitative study of their project-based mode of operations, we detail the six main ingredients of the collective competence that underpins the activities of commando units in the field and insist upon the criticality of the pre- and postmission phases during which this collective competence is actively reinforced.