At-will employment is a doctrine of American law that defines an employment relationship in which either party can terminate the relationship with no liability if there was no express contract for a definite term governing the employment relationship. Under this legal doctrine:
any hiring is presumed to be "at will"; that is, the employer is free to discharge individuals "for good cause, or bad cause, or no cause at all," and the employee is equally free to quit, strike, or otherwise cease work.
Several exceptions to the doctrine exist, especially if unlawful discrimination is involved regarding the termination of an employee.
Although at-will employment allows an employee to quit for no reason, the rule that either party can terminate the relationship is most often invoked when an employer wants to fire an employee at any time. Since this practice virtually eliminates job security, it can create an atmosphere of fear that may contribute to workplace bullying. However, there are limitations upon the employer's ability to terminate without reason. As a means of downsizing, say closing an unprofitable factory, a company may fire employees en masse."