Vulnerability as a Structural Condition: Consequence Without Normativity

This paper develops a structural account of vulnerability as the condition under which consequence becomes possible for systems capable of persistence, value, meaning, and purpose. The analysis operates strictly downstream of Informational Ontology (IO) revision 5i and introduces no new regime levels, primitives, or normative commitments. Vulnerability is treated neither as affective sensitivity nor as moral status. It is defined as lineage-relevant susceptibility to irreversible or asymmetrically recoverable loss: the structural possibility that some perturbations can permanently narrow a system's future reachability or degrade its capacity to maintain identity. On this basis, the paper distinguishes consequence from mere change, explains how harm can be real without being morally wrong, and clarifies why purposive organization makes "having something at stake" structurally unavoidable. The account stabilizes downstream IO analyses of responsibility, witnessing, legitimacy, and regime failure by isolating a presupposition implicit throughout that arc: responsibility attribution is coherent only where there exists a vulnerable locus such that consequences can terminate in a way that matters to future reachability and identity persistence.