Also known as: vis illicitae · unlawful force
Written by attorneys · grounded in primary & secondary sources — see below
Force, including confinement, employed without the consent of the person against whom it is directed when its use constitutes an offense or actionable tort.
Silas threatened to throw Ida from the crane cab twenty stories above ground unless she lifted an overloaded pallet. Ida complied by operating the crane in violation of safety rules. The threat of being hurled from the building constituted vis illicita that a person of reasonable firmness could not resist.
Carl marched onto Luis's property and advanced while brandishing a heavy wooden stake. Luis swung a shovel once at Carl's arm to knock the stake away. Carl's aggressive advance with the stake supplied the vis illicita that justified Luis's responsive force.
Select any source to read its text and confirm it supports the definition.
The husband repeatedly beat and threatened the defendant over many years. On the day of the killing he advanced on her while she was immobilized by fear. The pattern of unlawful physical attacks supplied the vis illicita that supported her claim that deadly force appeared necessary.
Vis illicita exists only when force is used without consent and its employment would constitute an offense or tort absent a defense such as duress or youth. Lawful force, by contrast, carries a privilege that prevents it from qualifying as vis illicita. The distinction determines whether a defendant may claim justification or excuse.
A threat qualifies only if it is immediate and of a character that a person of reasonable firmness in the actor's situation could not resist. Remote or conditional threats ordinarily fall short because they do not meet the immediacy and irresistibility requirements.
Modern codes provide that force used to resist a known arrest by a peace officer is not justified even if the arrest is later held unlawful. The policy channels disputes about arrest validity into the courts rather than physical confrontations.
…in the Comments to the Model Penal Code: "The actor must believe that his defensive action is immediately necessary and the unlawful force against which he defends must be force that he apprehends will be used on the present occasion, but he need not apprehend that it will be immediately used." Model Penal Code § 3.04 comment…