Definition
In Roman civil law, an actio prescriptis verbis was a form of action available to enforce obligations arising from innominate contracts — that is, contracts that did not fall within the recognized named categories of Roman law (sale, hire, loan, and the like). The action derived its legal force from continued usage and the opinions of learned jurists (the responsa prudentium), and was grounded in the unwritten law rather than in any specific enacted statute or edict. The phrase translates roughly as "action in prescribed words," referring to the practice of describing the particular facts of the transaction in the pleading itself, since no standard formula existed for the unnamed agreement.
The action served as a practical workaround: where a party had performed under an agreement that the formal law did not recognize by name, Roman jurists permitted recovery through this vehicle, allowing the pleader to set out the specific terms and circumstances of the transaction in place of a fixed, predetermined formula.
Common Confusion
Actio prescriptis verbis and actio in factum are closely related and are sometimes treated as interchangeable in secondary sources. They are distinct. The actio in factum was not grounded in custom or unwritten law; it instead proceeded by analogy to or on the equity of some existing, recognized law. The actio prescriptis verbis drew its authority from usage and juristic opinion independent of any specific analogized statute. In practice, both served to fill gaps left by the nominate action system, but their theoretical foundations differed. Researchers encountering either term in historical sources should not assume the two are equivalent without examining the underlying authority.
Why It Matters in Research
This is a term encountered almost exclusively in historical and comparative legal sources — treatises on Roman law, early equity jurisprudence, and scholarship tracing the civilian influence on common law and equity. Several points matter for corpus navigation:
First, the term appears in discussions of innominate contracts, a topic that surfaces in equity history when scholars trace how courts of equity handled agreements falling outside common law's recognized contractual categories. Researchers working on the history of unjust enrichment, quasi-contract, or early equity doctrine may encounter actio prescriptis verbis as part of that intellectual genealogy.
Second, the distinction between this action and actio in factum, noted by both Black's and Bouvier's, is a point where historical sources are not always consistent. Some civilian writers collapse the two; others maintain the distinction carefully. Spence's Equitable Jurisdiction (cited by both dictionaries) is the specific source underlying both dictionary entries, meaning both Black's and Bouvier's are drawing from the same passage. Researchers should go directly to Spence when precision is needed rather than relying on either dictionary as an independent authority.
Third, the term has no operational role in modern common law practice. Its relevance is purely doctrinal-historical. It should not be imported into any modern legal argument without substantial qualification, and its appearance in a modern context almost certainly signals a comparative law or legal history discussion.
Historical Dictionary Support
Black's Law Dictionary and Bouvier's Law Dictionary give essentially identical entries, both citing 1 Spence, Eq. Jur. 212. This is not coincidence — it reflects standard nineteenth-century dictionary practice of shared sourcing rather than independent research. Neither dictionary adds substantive analysis beyond that passage.
Bouvier's is marginally more useful for the researcher because it explicitly states the distinction between actio prescriptis verbis and actio in factum, noting that the latter was "founded not on usage or the unwritten law, but by analogy to or on the equity of some subsisting law." Black's omits this contrast entirely. For any research question turning on the difference between the two actions, Bouvier's is the more informative of the two shelf sources, though both ultimately route back to Spence.
Neither dictionary addresses the broader Roman law context of innominate contracts or situates the action within the full taxonomy of Roman civil actions. For that context, civilian sources and Roman law scholarship are necessary complements.
Jurisdictional Note
This term has no jurisdiction-specific application in any American or English common law system. It is a Roman civil law concept. Its relevance in American legal sources is limited to equity history and comparative law scholarship, primarily in the eighteenth and nineteenth centuries.