Definition
Locatio rei (Latin: "a letting of a thing") is a civil law term denoting the bailment or hiring of a tangible thing, whereby the owner (locator) delivers the thing to another (conductor) for use, in exchange for compensation. The conductor acquires the right to use the thing for the agreed period or purpose but does not acquire ownership. At the conclusion of the arrangement, the thing must be returned.
Locatio rei is one of the three classical subdivisions of locatio conductio — the broader Roman law category governing contracts of hire. The other two are locatio operis faciendi (hiring of work or services) and locatio operis mercium vehendarum (hiring for the carriage of goods). Locatio rei corresponds most closely to what common law systems call a bailment for hire or, in modern commercial usage, a rental or lease of personal property.
Common Confusion
Locatio rei is frequently encountered alongside its sibling terms locatio operis faciendi and locatio conductio without clear distinction in older treatises. Researchers should also take care not to conflate locatio rei with commodatum. In commodatum, the bailee receives the thing for use gratuitously — no compensation passes. Locatio rei requires consideration; the moment compensation is absent, the transaction shifts to commodatum. Historical sources sometimes use "locatio" loosely to cover the entire locatio conductio family, which can obscure which specific subspecies an author is discussing.
Core Elements
Locatio rei has three constituent elements that must be present for the transaction to qualify:
1. DELIVERY OF A THING: The locator must transfer possession of a specific tangible thing to the conductor. The thing must be capable of being used without being consumed; consumables that are destroyed in use are not properly the subject of locatio rei.
2. RIGHT OF USE: The conductor acquires possession and the right to use the thing for the agreed purpose or duration. Ownership remains with the locator throughout.
3. COMPENSATION (MERCES): The conductor must pay — or agree to pay — the locator for the use. This distinguishes locatio rei from commodatum (gratuitous loan for use) and from mutuum (loan of fungibles where title passes).
Why It Matters in Research
Locatio rei appears most heavily in civil law treatises and in common law scholarship that draws on Roman law foundations to systematize bailment doctrine. Researchers working in nineteenth-century American or English legal literature will encounter it primarily in the company of Story on Bailments and Kent's Commentaries, both of which use the Roman taxonomy to organize what common law cases treat unsystematically.
The practical trap for corpus researchers is terminological layering. A source may use "locatio rei," "hire of a chattel," "bailment for hire," or simply "hiring" to describe the same transaction. These terms do not always map neatly across jurisdictions or time periods. Early American courts occasionally imported civil law vocabulary through Kent and Story, then abandoned it as domestic bailment doctrine matured; later sources drop the Latin entirely.
Researchers examining insurance, carrier liability, or lease-of-goods questions in historical materials should treat locatio rei as a signal that the author is working within a civilian analytical frame. The obligations the text assigns to locator and conductor may differ subtly from what a common law court would impose on bailor and bailee — particularly on questions of fault, the standard of care, and liability for loss. Do not assume direct doctrinal equivalence without checking whether the source is reasoning from Roman law, civilian commentary, or common law precedent.
Historical Dictionary Support
The three source dictionaries are in close agreement: all define locatio rei as a letting of a thing to hire, and both Black's and Burrill's draw the same language from Kent's Commentaries and Story's treatise on bailments. Rapalje & Lawrence offer only the compressed gloss "the hiring of a thing," which is accurate but strips out the bailment framework that gives the term its doctrinal content.
None of the historical sources address the procedural or remedial dimensions of locatio rei — specifically, the actio locati (available to the locator) and the actio conducti (available to the conductor) that Roman law provided to enforce the arrangement. For researchers tracing how civilian remedies were or were not received into American practice, the dictionary sources are insufficient and should be supplemented with Story's Bailments directly and with treatises on the civil law such as those of Pothier, whose influence on Story is well documented.
Jurisdictional Note
Locatio rei as a term of art is most at home in civil law jurisdictions (Louisiana, Quebec, and comparative law scholarship) and in historical common law treatises drawing on civilian sources. In modern Anglo-American practice the concept survives entirely under common law bailment and commercial lease doctrine, and the Latin terminology has effectively disappeared from pleadings and judicial opinions.