Definition
Facio ut facias (Latin: "I do that you may do") is a term from Roman and civil law identifying one of the four classical innominate contracts — agreements that did not fall neatly within the named categories of Roman contract law (sale, hire, loan, etc.) but were nonetheless enforceable. A facio ut facias contract arises when two parties exchange acts or forbearances: each party performs, or agrees to perform, some act in consideration of the other party doing likewise. The paradigmatic example is a mutual labor exchange — I agree to work your land if you agree to work mine. A promise of marriage (two parties each agreeing to marry the other) was also classified under this form. The consideration running between the parties is act for act, as opposed to money for act or thing for act.
Common Confusion
Facio ut facias is one of four innominate contract formulas in Roman civil law. The full set is: facio ut facias (act for act), facio ut des (act for thing), do ut facias (thing for act), and do ut des (thing for thing). Researchers occasionally conflate these, particularly facio ut facias and facio ut des. The distinction turns on what the second party gives in return: in facio ut facias, the counter-performance is also an act; in facio ut des, the counter-performance is a transfer of property or money. The difference matters in historical legal sources that analyze enforceability and remedy under each category separately.
Why It Matters in Research
This term appears almost exclusively in sources treating the civil law tradition — Roman law, canon law, early English common law borrowings from civil law scholarship, and treatises on contract formation. Researchers working in pre-nineteenth-century English contract law, particularly on the doctrine of consideration, will encounter facio ut facias when sources analogize common law bilateral executory contracts to the Roman innominate contract framework.
The practical trap for corpus researchers is that the term drops almost entirely from primary legal sources after the consolidation of modern consideration doctrine in English and American common law. Courts and treatises after roughly the mid-nineteenth century ceased to classify bilateral contracts using the Roman taxonomy. A researcher finding facio ut facias in a modern source is almost certainly looking at a civil law jurisdiction, a comparative law work, or a historical treatise.
The Bracton and Fleta references in Burrill's entry are significant navigational markers: these medieval English law texts drew heavily on Roman civil law, and their use of this term reflects the civilian influence on early common law contract thinking — an influence that largely receded as common law consideration doctrine matured. Corpus searches touching early medieval contract formation should be paired with attention to both the Latin formula and its English paraphrase equivalents.
Because the term belongs to a family of four parallel formulas, searches should typically extend to all four: do ut des, do ut facias, facio ut des, and facio ut facias. Sources treating one usually treat the others in proximity.
Historical Dictionary Support
All three source dictionaries present substantially identical definitions, all tracing to the same passage in Blackstone's Commentaries (2 Bl. Comm. 444). This convergence reflects the term's settled, non-contested nature in legal reference literature: it names a recognized civil law category with a fixed meaning and no significant interpretive dispute.
Burrill's entry adds the most useful research scaffolding, citing not only Blackstone but the Digest (Dig. 19. 5. 5), Bracton, and Fleta — pointing researchers directly to primary civil law and medieval common law sources where the term appears in context. Black's entries (both first and second editions) are functionally identical and add no new analytical content beyond Blackstone's formulation.
One notable gap: none of the historical dictionaries addresses the remedial implications of the innominate contract classification under Roman law — specifically, the actio praescriptis verbis that enforced such contracts. Researchers needing that dimension should consult Roman law treatises directly rather than relying on these common law dictionary entries, which treat the term primarily as a classificatory label rather than as a vehicle for doctrinal analysis.
The mention of forbearance ("it may be to forbear on one side in consideration of something done on the other") in the Black's entries is worth attention. This extends facio ut facias beyond purely affirmative mutual acts and edges toward the common law concept of forbearance as consideration — a point of conceptual connection that historical sources note but do not develop.