As a general rule the courts have adopted a wide interpretation in establishing what is not in the course of employment. If the employee’s act was not carried out in the course of employment, he will be deemed to have been on a ‘frolic of his own’ (Joel v Morrison (1834) 6 C & P 501) and the employer will not be vicariously liable. This is so if an employee acts outside the scope of his employment, i.e. does something he is not authorised to do or performs an act he is expressly prohibited from carrying out.