Legal scholars distinguish two modes of international legal cooperation: minimum legal harmonization and full harmonization (i.e. legal unification). These cooperative choices imply more or less stringent requirements and are opposed to non cooperative, unilateral legal changes. This paper is an attempt to model these alternative modes of legal adjustments and to compare their properties regarding legal convergence. We show that all arrangements can lead to legal uniformity. We also show that decentralized processes can be better than more centralized arrangements.