Definition
An action of fraud in Roman civil law. The actio de dolo malo was the remedy available to a person who had been defrauded, brought against the defrauder — and, significantly, against the defrauder's heirs where they had been enriched by the fraud — to recover either the thing wrongfully taken (together with all its accessions, expressed in the sources as cum omni causa) or, where restoration in kind was impossible, compensation in damages. The action was penal in character. It was subsidiary in nature, meaning it lay only where no other adequate legal remedy existed. The underlying concept of dolus malus — bad faith or intentional deceit — distinguished this action from remedies rooted in mistake or negligence.
Common Confusion
Researchers should distinguish the actio de dolo malo from two related civil law concepts. First, the exceptio doli was a defensive plea, not an offensive action: a defendant invoked it to block enforcement of a claim tainted by the plaintiff's own fraud. Second, dolus as a general concept in Roman law encompassed both the substantive element of fraudulent intent and the procedural remedies built around it. The actio de dolo malo is specifically the offensive, plaintiff-side action for fraud — one piece of a broader Roman law architecture around deceit.
Why It Matters in Research
This term appears almost exclusively in sources dealing with Roman civil law and its reception into civil law jurisdictions — primarily Continental European systems and, in the Anglo-American tradition, in treatises and legal dictionaries that trace doctrinal history. Researchers using Law Mind sources will encounter it most in comparative law contexts, historical treatments of fraud doctrine, and civilian-influenced jurisdictions.
Several research traps are worth flagging. First, the term is Latin and not translated consistently across sources: some dictionaries render it as "action of fraud," others use "action for deceit." Searching only translated forms will miss the Latin heading under which most historical entries are organized. Second, the penal and subsidiary character of the action matters for understanding how historical sources frame fraud remedies: the action did not simply replicate contract or delict remedies but filled gaps where those remedies failed. Third, the extension of liability to enriched heirs is a feature that distinguishes this action from many common law fraud doctrines and is worth noting when tracing the divergence between civil and common law approaches to third-party liability for fraud.
For researchers working through the Law Mind corpus on the history of equitable fraud, unjust enrichment, or the development of good faith obligations, the actio de dolo malo is a useful doctrinal ancestor and a point of contrast with common law equivalents.
Historical Dictionary Support
The three source dictionaries are in substantial agreement. All three identify this as a civil law action of fraud. Burrill's entry is the most substantive, specifying the scope of recovery (restitution of the thing with all accessions, or damages where restitution was impracticable), the extension of liability to enriched heirs, and citing Mackeldey's Civil Law and Heineccius's Elementa Juris Civilis as authority. Bouvier adds the important procedural detail that the action was originally limited to one year and that Constantine extended it to two years — a note absent from both Black's and Burrill's entries as excerpted here. Black's entry as preserved in the source material is truncated.
What the historical dictionaries collectively underemphasize is the subsidiary nature of the action — its availability only in the absence of another adequate remedy — which is a defining structural feature in the Roman law sources. Researchers relying solely on dictionary definitions risk missing that limitation. The civilian treatises cited by Burrill (Mackeldey and Heineccius) remain the better starting point for substantive analysis of the doctrine's operation.
Jurisdictional Note
The actio de dolo malo has no direct counterpart in English common law, which developed fraud and deceit through separate doctrinal channels. Its relevance in modern research is primarily historical and comparative. Civil law jurisdictions influenced by Roman law absorbed and transformed the underlying doctrine; the specific procedural action did not survive as a named remedy in modern codes.