A policy concern underlying the imposition on defendants of a liability in tort which influences the courts, sometimes expressly and sometimes implicitly, is a need to protect and assist persons who may be seen to have been in a vulnerable position at the time they suffered injury or harm. Leading decisions concerning the imposition on defendants of a duty of care in negligence, of vicarious liability in respect of the deliberate or negligent actions of another person, and of a duty which cannot be delegated to another person, all have given expression to, and support for, a concept of plaintiff vulnerability. Indeed, recent decisions in the United Kingdom, Canada and Australia concerning the abuse of children by persons in a position of power and authority and which significantly extend the reach of vicarious liability provide particularly apt examples. The aim of this article is to show how the three different kinds of claim can provide a remedy for vulnerable people and to identify any links and overlaps between them. Certainly it is apparent that the idea of vulnerability can provide helpful guidance for a court faced with a novel or borderline question of liability.