Definition
A Roman civil law action brought against a father or master (paterfamilias or dominus) to recover on contracts made by a person under their legal authority — a son (filius familias) or slave — but only to the extent of that person's peculium: the separate fund or property that the father or master had permitted them to hold and manage as their own. The action did not expose the superior party to unlimited liability; recovery was capped at the value of the peculium at the time judgment was rendered.
The term is Latin: actio (action at law) de peculio (concerning the peculium). Its function was to provide creditors a limited remedy against a household authority figure when the subordinate party who made the contract lacked independent legal standing to be sued or to hold property in their own right.
Why It Matters in Research
This term appears almost exclusively in sources treating Roman law, civil law systems derived from Roman tradition, and comparative legal history. Researchers encountering it in English-language legal materials are most likely working in one of three contexts: (1) 19th-century American or English treatises on civil law foundations, where Roman actions were catalogued as background to equity and contract doctrine; (2) Scottish, Louisiana, Quebec, or South African legal sources, where civilian heritage makes such terminology more operationally relevant; or (3) historical scholarship on the legal status of slaves, children, and dependent persons.
The critical navigational point is the cap on recovery. Unlike modern vicarious liability or respondeat superior — which can expose a principal to the full measure of damages — the actio de peculio was structurally limited. Researchers comparing Roman law to common law agency or master-servant doctrine must hold this distinction firmly: the Roman action tracked the asset pool, not the full economic exposure of the superior party. Conflating the two will produce misleading comparative analysis.
Researchers should also be aware that the peculium itself was a contested legal concept: the father or master retained ultimate ownership, but the dependent had practical management authority. This tension — between formal ownership and functional control — is sometimes treated as a precursor to trust and agency concepts, and encyclopedia and treatise entries on those topics may reference actio de peculio without making the connection explicit.
Historical Dictionary Support
All three source dictionaries agree on the essential structure: an action against a father or master, limited to the value of the subordinate's peculium. Burrill's entry is the most complete, citing the Institutes (4.6.10; 4.7.4), the Digest (15.1), the Code (4.26), and Heineccius's Elementa Juris Civilis — the standard 18th-century civilian systematic treatise — as authority. Black's and Bouvier's offer condensed versions without citations. Bouvier's is notable for specifying "fathers and masters" as liable parties, which usefully emphasizes that the action applied to both freeborn dependents and slaves, though Bouvier frames this without distinguishing the two relationships.
None of the three entries explain what happens when the peculium is insufficient to satisfy the claim, or the procedural relationship between the actio de peculio and related actions such as the actio de in rem verso (which allowed recovery beyond the peculium when the master or father was enriched by the transaction). Researchers relying only on these dictionary entries will miss the broader taxonomy of actions available against a paterfamilias on subordinate contracts.
Jurisdictional Note
The actio de peculio has no direct equivalent in common law jurisdictions, where it was never received. In Louisiana, Quebec, Scotland, and other mixed or civil law systems, the Roman taxonomy of praetorian actions retains historical and occasionally doctrinal relevance, and sources from those jurisdictions may treat the term with more technical precision than English or American materials.