Under the doctrine of private necessity, what is a trespasser liable for?

Under the doctrine of private necessity, a trespasser is liable for actual damages caused by the trespass. This principle exists because, while the doctrine allows a person to enter another's property without permission when necessary to prevent greater harm, it does not absolve them of responsibility for any damage they might cause during that entry.

For example, if a person enters a neighbor's property to seek shelter from a storm and accidentally damages the property in the process, they would be responsible for compensating the neighbor for that damage. The rationale is that while the trespass was justified by the necessity of the situation, the person still has an obligation to make good on any harm they have inflicted.

This liability contrasts with the idea that one might not be held accountable at all or only for punitive damages, which do not apply here since the necessity of the entry alters the nature of the trespass but does not eliminate responsibility for damages incurred.