Definition
Reus stipulandi is a Roman civil law term designating the creditor or obligee in a stipulatio — the formal oral contract of Roman law in which one party asked a question and the other gave a binding answer. The reus stipulandi is the party who posed the question and thereby acquired the right to receive performance. The counterpart, the reus promittendi, is the debtor or obligor who answered and thereby became bound to perform.
The term belongs to a paired vocabulary. Reus, in this context, does not carry its modern connotation of guilt or criminal accused; it means simply "party" — the person standing in a legal relation. Stipulandi is the genitive of the gerund of stipulari, meaning "of stipulating." Together, the phrase identifies the party on the receiving, or active questioning, side of the stipulatio transaction.
Where multiple creditors were jointly entitled under a single stipulation, they were collectively called correi stipulandi (joint rei on the creditor side). The corresponding plural for joint debtors was correi promittendi.
Common Language
This section is omitted. Reus stipulandi is pure Roman civil law terminology with no counterpart in ordinary modern English usage.
Common Confusion
Reus stipulandi is frequently encountered alongside reus promittendi and should never be conflated with either. The two terms are mirror images: the reus stipulandi holds the right (creditor/obligee); the reus promittendi bears the burden (debtor/obligor). Both are called reus, which causes confusion for researchers who first encounter reus in criminal law contexts where it means the accused or guilty party. In this contractual setting, reus is entirely neutral — it designates a party to a legal relationship, not a wrongdoer.
Researchers should also distinguish the reus pairing from the correi construction. Correi stipulandi and correi promittendi denote the plural, joint versions of the same roles. The shift from singular reus to plural correi is a structural feature of Roman stipulatio doctrine, not a different kind of obligation.
Why It Matters in Research
This term appears almost exclusively in sources treating Roman civil law and its reception into later civil law systems, particularly in comparative law texts, civil law jurisdiction treatises, and scholarly writing on the law of obligations. Researchers working in Louisiana, Quebec, or other mixed civil law jurisdictions may encounter stipulatio analysis that uses this vocabulary.
The principal trap for common law researchers is the word reus itself. In criminal law sources — including the Law Mind corpus — reus appears constantly as part of actus reus and mens rea, where it means the wrongful deed or the guilty mind. When reus stipulandi or reus promittendi surfaces in a civil law or obligations context, that criminal-law meaning is irrelevant and misleading. The two usages of reus are historically distinct and should be treated as separate vocabulary families.
Black's Law Dictionary and Rapalje & Lawrence both attribute the substantive explanation to Brown, a reference to Bouvier's Brown or a similar civilian law glossary, signaling that neither dictionary developed the definition independently. Researchers tracing the doctrinal substance should look beyond American legal dictionaries to civilian sources.
The correi concept — joint parties on either side of a stipulation — connects to later civil law treatment of joint and several obligations (solidary obligations in Louisiana terminology). If a research trail leads from reus stipulandi to questions about how multiple creditors or debtors share rights or liabilities, the relevant doctrinal body is the law of solidarity and joint obligations, not common law joint tenancy or joint and several liability as understood in American tort law.
Historical Dictionary Support
Black's Law Dictionary and Rapalje & Lawrence are substantively identical on this entry, and both trace to Brown. Neither source adds doctrinal depth beyond the definitional pairing. This convergence suggests the entry passed through the nineteenth-century American legal dictionary tradition as received material from civilian glossarists rather than from any independent American legal development.
What the historical dictionaries do not provide: any discussion of how the stipulatio itself functioned, the formal requirements of the oral exchange, how Roman jurists treated ambiguity in the question-and-answer form, or how the concept survived (or did not) in post-Roman civil law codifications. Researchers who need that context must go beyond American legal dictionaries entirely.
The historical dictionaries are reliable for the definitional pairing and the correi terminology. They are unreliable as a guide to the broader law of stipulatio or to modern civil law treatment of the concept.
Jurisdictional Note
This term is operative in Roman civil law and in legal systems derived from it. It has no recognized role in common law doctrine. In American law, the term appears only in historical, comparative, or academic writing. Louisiana civil law scholarship is the most likely domestic context where a researcher might encounter it in a legal (rather than purely historical) discussion.
Encyclopedia Cross-Reference
For the distinct criminal law uses of reus, see: Criminal Law — Elements of a Crime (Actus Reus and Mens Rea) and Criminal Law — Actus Reus (Voluntary Act Requirement), both in The Law Mind Criminal Law Encyclopedia. Note that those entries address an entirely different legal concept; they are cross-referenced here only to prevent confusion between the two usages of reus, not because they illuminate stipulatio doctrine.