Definition
A condictio certi is an action in Roman civil law to recover a fixed, certain sum or specific thing owed under a definite obligation. The action lies where a promise or stipulation (stipulatio) is certain — that is, where the subject matter of the obligation is precisely determined in amount, kind, or identity, leaving no room for estimation or assessment. The creditor claims that the debtor owes a specific, ascertainable thing, and the plaintiff's demand must be stated exactly.
The term breaks down descriptively: condictio refers broadly to a personal action to recover what is owed, and certi specifies that the object of the claim is certain (certa). Where the thing owed was uncertain or required valuation, a different form of action applied.
Why It Matters in Research
This term appears almost exclusively in sources treating Roman law, civil law systems, and the historical foundations of common law personal actions. Researchers encountering condictio certi in English legal sources are most likely reading medieval treatises — particularly Bracton or Fleta — where Roman procedural concepts were grafted onto early English legal reasoning. The term does not survive as a live procedural category in modern common law jurisdictions, but it is essential background for understanding the ancestry of the common counts in assumpsit and the general architecture of debt actions.
A key research trap: condictio is a family of actions, not a single remedy. Sources may use condictio generically or may distinguish among condictio certi, condictio incerti, condictio indebiti, condictio sine causa, and others. Failing to track which condictio a source is discussing will produce confusion, particularly in comparative law scholarship or historical treatises where the distinctions carry substantive weight.
For corpus researchers, Burrill's citation trail — Inst. 3.16, Dig. 12.1, Bracton fol. 103b, Fleta — marks the primary source cluster. Any Law Mind materials touching early debt recovery, the common counts, or the Roman substratum of English law will likely intersect with this action or its relatives.
Historical Dictionary Support
Black's and Burrill's entries are functionally identical in substance, both anchoring the term to the requirement that the stipulation be certain (si certa sit stipulatio) and citing the same institutional sources in Justinian's Institutes and Digest. Burrill's entry is marginally more complete, extending the citation chain to Bracton and Fleta, which establishes the bridge between Roman procedure and medieval English practice — a connection Black's leaves implicit.
Neither entry expands on the procedural mechanics of how certainty was assessed, nor do they address the condictio certi's relationship to the condictio incerti or the broader taxonomy of Roman personal actions. For a researcher needing that analytical depth, the dictionary entries function as orientation points only; substantive treatment requires going to the Digest directly (Dig. 12.1) or to the institutional literature on Roman law.
Both sources agree on the essential definition without divergence. The historical record on this term is stable and narrow.
Jurisdictional Note
Condictio certi has no procedural life in modern common law jurisdictions. It retains relevance in civilian legal systems (particularly those with Roman law foundations, including Scots law and South African law) where the condictiones remain recognized categories of unjustified enrichment and personal obligation. Researchers working in mixed jurisdictions or comparative law contexts should not assume the common law treatment of debt actions maps cleanly onto the Roman category.