Volenti non fit injuria

Volenti non fit iniuria(orinjuria) (Latin: "to a willing person, injury is not done") is a Roman legal maxim andcommon lawdoctrine which states that if someone willingly places themselves in a position where harm might result, knowing that some degree of harm might result, they are not able to bring a claim against the other party intortordelict.Volentiapplies only to the risk which a reasonable person would consider them as having assumed by their actions; thus aboxerconsents to being hit, and to the injuries that might be expected from being hit, but does not consent to (for example) his opponent striking him with an iron bar, or punching him outside the usual terms of boxing.Volentiis also known as a "voluntary assumption of risk".
Volentiis sometimes described as the plaintiff "consenting to run a risk". In this context,volentican be distinguished from legalconsentin that the latter can prevent some torts arising in the first place. For example, consent to a medical procedure prevents the procedure from being atrespass to the person, or consenting to a person visiting one's land prevents them from being atrespasser.
Volenti non fit injuriais an often-quoted form of thelegal maximformulated by the Roman juristUlpianwhich reads in original:Nulla iniuria est, quæ in volentem fiat.
InEnglish tort law,volentiis afull defence, i.e. it fully exonerates the defendant who succeeds in proving it.The defence has two main elements:
It is not easy for a defendant to show both elements and thereforecomparative negligenceusually constitutes a better defence in many cases. Note however that comparative negligence is a partial defence, i.e. it usually leads to a reduction of payable damages rather than a full exclusion of liability. Also, the person consenting to an act may not always be negligent: abungee jumpermay take the greatest possible care not to be injured, and if he is, the defence available to the organiser of the event will bevolenti, not comparative negligence.
Consent to medical treatmentor consent to risky sportson the part of the claimant excludes liability in tort where that consent isinformed consent.
TheScots lawofdelictsimilarly recognises the principle and defence ofvolenti non fit injuria.
US tort law has a similar but more complex legal principle known asassumption of risk.  US law recognizes at least two major overlapping dichotomies between different kinds of assumption of risk (primary v. secondary, express v. implied).
In Canada, the "volentio" principles applies in much the same way as under English law.  The leading Canadian cases on point areDube v. LabarandHall v. Hebert.
TheOccupiers' Liability Act 1984(and in Scotland the Occupiers' Liability (Scotland) Act 1960) requires all owners of property to take reasonable steps to make their premises safe for anyone who enters them, even those who enter as trespassers, if they are aware of a risk on the premises.  However, the doctrine ofvolentihas been applied to cases where a trespasser exposed themselves deliberately to risk:
In the first case (decided before the Occupier's Liability Act was passed), a girl who had trespassed on the railway was hit by a train.  The House of Lords ruled that the fencing around the railway was adequate, and the girl had voluntarily accepted the risk by breaking through it.  In the second case, a student who had broken into a closed swimming-pool and injured himself by diving into the shallow end was similarly held responsible for his own injuries.  The third case involved a man who dived into a shallow lake, despite the presence of "No Swimming" signs; the signs were held to be an adequate warning.
The defence ofvolentiis now excluded by statute where a passenger was injured as a result of agreeing to take a lift from a drunk car driver. However, in a well-known case ofMorris v Murray,volentiwas held to apply to a drunk passenger, who accepted a lift from a drunk pilot. The pilot died in the resulting crash and the passenger who was injured, sued his estate. Although he drove the pilot to the airfield (which was closed at the time) and helped him start the engine and tune the radio, he argued that he did not freely and voluntarily consent to the risk involved in flying. The Court of Appeal held that there was consent: the passenger was not so drunk as to fail to realise the risks of taking a lift from a drunk pilot, and his actions leading up to the flight demonstrated that he voluntarily accepted those risks.
In New Zealand, in the case ofWalker v Watson,volentiwas held to apply to a situation where a car owner lent his car to someone who he knew was heavily intoxicated. The car ended up crashing into a wall, and the owner sued the driver for damages. The High Court held that the owner had voluntarily lent his car to a person who presented an obvious danger to his property, and therefore the owner was taken to have accepted the risk of damage to his car arising from drunk driving and had impliedly undertaken to bear any losses that arise.
For reasons of policy, the courts are reluctant to criticise the behaviour of rescuers.  A rescuer would not be consideredvolensif:
An example of such a case isHaynes v. Harwood,in which a policeman was able to recover damages after being injured restraining a bolting horse: he had a legal and moral duty to protect life and property and as such was not held to have been acting as a volunteer or giving willing consent to the action - it was his contractual obligation as an employee and police officer and moral necessity as a human being to do so, and not a wish to volunteer, which caused him to act. In this case the court of appeal affirmed a judgement in favor of a policeman who had been injured in stopping some runaway horses with a van in  a crowded street. The policeman who was on duty, not in the street, but in a police station, darted out and was crushed by one of the horses which fell upon him while he was stopping it. It was also held that the rescuer's act need not be instinctive in order to be reasonable, for one who deliberately encounters peril after reflection may often be acting more reasonably than one who acts upon impulse.
By contrast, inCutler v. United Dairiesa man who was injured trying to restrain a horse was held to bevolensbecause in that case no human life was in immediate danger and he was not under any compelling duty to act.
Also, although to be a "neighbour" within Lord Atkin's dictum, a claimant must be "so closely and directly affected by one's act that one ought reasonably to have them in contemplation", rescuers are invariably deemed to be neighbours, even if their presence would objectively seem to be somewhat unlikely -Baker v Hopkins.
Examples of cases where a reliance onvolentiwas unsuccessful include:
In the first case, theplaintiffwas an instructor who was injured while teaching the defendant to drive. The defence ofvolentifailed: that is, because the plaintiff specifically inquired if the defendant's insurance covered him before agreeing to teach. In the second case, a doctor went in to try to rescue workmen who were caught in a well after having succumbed to noxious fumes. He did so despite being warned of the danger and told to wait until the fire brigade arrived. The doctor and the workmen all died. The court held that it would be "unseemly" to hold the doctor to have consented to the risk simply because he acted promptly and bravely in an attempt to save lives.
Generally courts are reluctant to recognise voluntary assumption of risk. An example of a court reluctant to find a voluntary assumption of risk includesCarey v Lake Macquarie City Council.Instead the conduct amounted tocontributory negligence, which is not a complete defence.