Civil Liability Act 2002

A person is not negligent in failing to take precautions against a risk of harm unless—

the risk was foreseeable (that is, it is a risk of which the person knew or ought to have known), and

the risk was not insignificant, and

in the circumstances, a reasonable person in the person’s position would have taken those precautions.

In determining whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (amongst other relevant things)—

the probability that the harm would occur if care were not taken,

the likely seriousness of the harm,

the burden of taking precautions to avoid the risk of harm,

the social utility of the activity that creates the risk of harm.