Based on biographical materials of armed militants of the Provisional Irish Republican Army and Red Brigades, this article analyses variation within the micromobilization that leads to armed groups. Three general paths are singled out: the ideological path, the instrumental path and the solidaristic path. Each of these is characterized by complex interactions between the individual motivations for involvement (micro-level), the networks that facilitate the recruitment process (meso-level), and the effects of repression on individuals (macro-level). We discuss the discoveries we have made and conclude by describing the advantages of our approach.