Definition
An adverse event or calamity arising by accident — without the will or concurrence of the person who suffers it — and of a character that could not reasonably be foreseen or guarded against by ordinary care and prudence.
In law, misfortune carries a specific additional dimension beyond mere bad luck: the person whose act produces harm must not have been engaged in an unlawful act at the time. This is especially significant in homicide law, where a killing attributable to misfortune — as distinct from negligence, recklessness, or criminal conduct — may excuse the actor from criminal liability entirely. The term is closely aligned with accident and misadventure, though each carries its own technical weight.
Common Language
Modern common usage (Wiktionary): Bad luck; an undesirable event such as an accident.
Historical common usage (Webster's 1913): Bad fortune or luck; calamity; an evil accident; disaster; mishap; mischance.
The ordinary meaning and the legal meaning share a core — something bad that happens outside a person's deliberate control — but the legal definition imposes two conditions the common language does not: first, that the event was not merely unexpected but genuinely unforeseeable by a reasonably prudent person; and second, in the homicide context, that the actor was engaged in a lawful activity at the time. A person struck by lightning while committing robbery does not suffer "misfortune" in the legal sense on behalf of whoever else is harmed as a result. That lawfulness requirement is invisible in everyday use and is the primary trap for researchers.
Common Confusion
MISFORTUNE, ACCIDENT, and MISADVENTURE are used interchangeably in common speech and sometimes loosely in older legal texts, but they are not synonymous in legal doctrine. Accident emphasizes the unforeseen and unintended character of the event without necessarily implying lawful conduct. Misadventure is the older, more technical term used specifically in homicide — a killing by misadventure (also called homicide per infortunium) describes death caused while the actor is doing a lawful act, without any intention to harm. Misfortune is the broader, more general term from which misadventure can be seen as a subset. Researchers encountering any of these terms in historical sources should not assume they are interchangeable without checking the doctrinal context.
Why It Matters in Research
The legal significance of misfortune is most concentrated in criminal law, particularly the law of homicide, where it functions as a complete defense. Understanding how a jurisdiction defines misfortune — and how that definition interacts with unlawful-act doctrine — is essential for reading older cases accurately.
Several research traps are worth flagging:
The lawful-act requirement is the pivotal condition. Historical sources often state the rule as self-evident, but the boundary between lawful and unlawful conduct shifted over time as criminal statutes expanded. A 19th-century act classified as lawful may have been criminalized by statute in the 20th century, changing the applicability of the misfortune defense without any change to the doctrine itself.
The foreseeability standard embedded in misfortune connects directly to the development of negligence doctrine. Bouvier's formulation — that the event must be "of so improbable a character that no prudent man would take it into his calculations" — anticipates the reasonable person standard. Researchers working on the intellectual history of negligence will find misfortune a useful upstream source.
Anderson's Dictionary offers no independent definition, pointing instead to Accident, Homicide, and Misadventure. This is not an omission to ignore: it signals that by the late 19th century, misfortune as a standalone term was losing doctrinal specificity and being absorbed into those neighboring categories.
Corpus researchers should also note that misfortune appears frequently in equity contexts — particularly in petitions seeking relief from forfeiture or strict enforcement of contracts — where it functions less as a technical term and more as a narrative appeal to equitable discretion. Distinguishing these two uses (technical criminal law defense versus equitable plea) is necessary when searching across case law archives.
Historical Dictionary Support
Black's Law Dictionary (both editions) and Bouvier's Law Dictionary present essentially the same definition, all drawing on 20 Q.B. Div. 816. The two conditions — unforeseeability and lawful conduct at the time — appear consistently across these sources, suggesting settled agreement among American and English legal lexicographers on the term's core meaning.
Bouvier adds the "prudent man" framing, which is the more precise articulation of the foreseeability element and the most useful formulation for connecting misfortune to later negligence doctrine. Black's references 4 Bl. Comm. 182, grounding the term in Blackstone's treatment of homicide — specifically the distinction between excusable homicide by misadventure and justifiable homicide, with accidental killing during a lawful act falling into the excusable category.
What the historical dictionaries do not address: the defense's interaction with felony-murder doctrine, the treatment of misfortune in civil as opposed to criminal contexts, and the erosion of the category under modern criminal codes that replaced common-law homicide classifications with statutory frameworks. Researchers relying solely on dictionary sources will miss these developments.
Jurisdictional Note
Common-law jurisdictions that retain the excusable homicide framework (homicide per infortunium) treat misfortune as a recognized category. Many American states have replaced this common-law classification with statutory schemes in which misfortune, as such, does not appear — the concept survives instead through accident defenses, absence-of-mens-rea arguments, or specific statutory provisions. English law retains closer continuity with the historical framework.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Homicide; Accident; Negligence