Vicarious liability refers to legal responsibility for tort actions committed by someone else. In other words, under this doctrine, a person or entity can be held liable for someone else's actions. This type of liability, also referred to as secondary liability, is vested in agency law.
Vicarious liability exists under the doctrine of respondeat superior. This doctrine dictates that the master is responsible for the actions of his agent. The agent can also be held legally responsible, so both parties can be sued and found jointly or severally liable for damages.
Vicarious liability is commonly found in an employment law situation. If an employee commits a tort that is within the scope of his employment, the employer can be held liable. In other words, if an employee injures someone or commits a tort while he is doing his job, the injured victim can sue the employer.
Vicarious liability is a form of strict liability. This means that the "master" or employer, did not have to intend for the tort to be committed. Even if the employer intended for the employee to behave responsibly and not commit torts, the employer can still be legally responsible.
An employer can protect itself from vicarious liability by imposing strict guidelines as far as acceptable behavior. An "agent" or employee is said to be outside of the scope of his employment if he acts outside of his job duties. If a company makes clear what the job duties are, and limits the scope of employment, this can provide some measure of protection against this type of secondary liability being imposed.
Certain other limits also apply to the secondary liability imposed upon employers. For example, if an employee willfully commits assault or battery, the employer is not usually held legally liable for this action. Exceptions to this exist, however, if the use of force was directed by the employer, or was a part of the employee's job.
Secondary liability is designed to encourage a "master" to monitor the actions of those representing him. In addition, since corporations are not themselves people, their only persona can be through their employees. It thus makes sense that a corporation who has employees who periodically engage in illegal or irresponsible actions must be able to be held legally liable for the encouragement of those inappropriate actions.
Secondary liability can also exist in other agency contexts outside of the employment relationship. For example, if one person lends another his car to do an errand for him, the person whose car it is can be held responsible for the actions of the person who borrowed the car. The person who borrowed the car is essentially acting as an agent, thus vicarious liability is appropriate in this context.