Literally a frolic means to engage in light hearted fun activities. Legally, it is sometimes used in the context of acts of employees or agents that an employer or principal wishes to deny legal responsibility for, or assert were unauthorised and/or ultra vires. The defence may work if the activity that the employer or agent is being held responsible for is fairly clearly not part of the employees or agent’s responsibilities, duties or role. It is weaker if it is activity that might reasonably be perceived as forming part of the tasks or responsibilities the employee or agent might reasonably be expected to fulfil.