This work proposes a structural foundation for the universal laws of multi-scale complexity introduced by Siegenfeld and Bar-Yam (Entropy, 2025). Their formulation describes the complexity profile, the multi-scale law of requisite variety, and the sum rule as phenomenological regularities, but leaves their physical origin unspecified. Here we interpret these laws as consequences of a phase-topological principle: the minimal action bound for distinguishability, δS ≥ ħ. Within this framework, three structural results follow: (i) a capacity bound limiting the number of coherent supports in a region by its available action budget, corresponding to the requisite variety condition; (ii) a balance principle showing that the total action budget provides a fixed constraint that can be redistributed across scales, underlying the sum rule; and (iii) a projection rule expressing the phenomenological complexity profile as the per-scale entropy increments of a structural distinction measure. Together, these results suggest that phenomenological complexity laws emerge as consequences of a single action principle, analogous to how thermodynamic irreversibility arises from statistical mechanics. By explicit analogy with Landauer’s bound for erasure, we interpret ħ as the minimal action cost of distinction, providing a possible structural route toward unifying complexity science with the broader physical context of quantized action and finite informational capacity.