In most instances, an employment contract will not state its expiration date. In such a case, the contract may be terminated at any time by either party. If the employment contract does not have a definite duration, it is terminable at will. This is called employment at will. Under the employment at will doctrine, the employer has historically been allowed to terminate the contract at any time for any reason or for no reason. Some State Courts and some State Legislatures have changed this rule by limiting the power of the employer to discharge the employee without cause.