Although the interrelations between the state institution and the emergence of political violence affect many different forms of contentious politics, in the case of terrorism this issue comes out to be even more crucial, since the violence from the underground is the main, if in not the only, repertoires of contention conceptualized and deployed in challenging existing structures of ruling power. Moving from this assumption, this paper investigates how specific notions of state and power can shape those framing processes of political violence elaborated by clandestine organisations, determining, in turn, the activation of specific violent repertoires of action. The phenomenon of the left-wing armed struggle in the Italian late Seventies is taken as a case of study, focusing on the two most important terrorist groups, namely the Red Brigades (BR) and Front Line (PL). The analysis revolves around two distinct aspects of the armed activity from the underground. Firstly, it will be considered how these two groups related to this crucial issue, analysing the ideas of state they conceptualised. The aim is to understand the modalities in which certain conceptualizations of power can contribute to mould the political perspectives of terrorist organisations and the meaning of their political project, emphasising analogies and differences between the two groups. The second aspect regards then the outcomes of such concepts of state and the modalities in which they the can determine the activation of violent repertoires from the underground. At this regard, some significant violent actions carried out by BR and PL in relation to state actors will be considered, examining how particular discourses on state influenced the choice of the targets of violence. Regarding political violence as a contextual and relational phenomenon, two elements will be taken into particular account in the analysis. On the one end, attention will be paid to the crisis of the Seventies and the related structural transformations of the Italian society, which deeply influenced the concept of state developed both by BR and PL. On the other, it will be considered the role played by the oppositional movements from below, which in the same years debated intensively about the issue of power. Focusing on the autonomia operaia (Workers Autonomy), a radical-leftist political area arising in the second half of the Seventies, it will be analysed how the social movements influenced the discourses on state elaborated by the BR and PL, for which the dynamics of the collective action from below were a fundamental reference point for constructing, motivating and legitimating violent repertoires. Conducting an internal qualitative analysis through the examination of the document produced by BR and PL, this paper has two main aims. Firstly, to investigate the role played by certain concepts of state in shaping contents and forms of clandestine political violence. Secondly, to examine to what extent these dynamics can vary in the context of the same social formation and within the same political-ideological family, trying to understand the origins of this variance degree and its effects on the political praxis of terrorism organisations.