“Legalization” refers to a particular set of characteristics that institutions may (or may not) possess. These characteristics are defined along three dimensions: obligation, precision, and delegation. Obligation means that states or other actors are bound by a rule or commitment or by a set of rules or commitments. Specifically, it means that they are legally bound by a rule or commitment in the sense that their behavior thereunder is subject to scrutiny under the general rules, procedures, and discourse of international law, and often of domestic law as well. Precision means that rules unambiguously define the conduct they require, authorize, or proscribe. Delegation means that third parties have been granted authority to implement, interpret, and apply the rules; to resolve disputes; and (possibly) to make further rules.

Each of these dimensions is a matter of degree and gradation, not a rigid dichotomy, and each can vary independently. Consequently, the concept of legalization encompasses a multidimensional continuum, ranging from the “ideal type” of legalization, where all three properties are maximized; to “hard” legalization, where all three (or at least obligation and delegation) are high; through multiple forms of partial or “soft” legalization involving different combinations of attributes; and finally to the complete absence of legalization, another ideal type. None of these dimensions – far less the full spectrum of legalization – can be fully operationalized.