The Civil Servants Act of Pakistan 1973

Section 3 of Civil Servants Acts 1973 deals with Terms and conditions.
(1) The terms and conditions of service of a civil servant shall be as provided in this Act and the rules.
(2) The terms and conditions of service of any person to whom this Act applies shall not be varied to his disadvantage.

civil servant” means a person who is a member of an All­Pakistan Service or of a civil service of the Federation, or who holds a civil post in connection with the affairs of the Federation, including any such post connected with defense, but does not include —
(i) a person who is on deputation to the Federation from any Province or other authority;
(ii) a person who is employed on contract, or on work­charged basis or who is paid from contingencies; or
(iii) a person who is a “worker” or “workman” as defined in the Factories Act, 1934 (XXV of 1934), or the Workmen’s Compensation Act, 1923 (VIII of 1923).

Selection authority means the Federal Public Service Commission, a departmental selection board, departmental selection committee, or other authority or body on the recommendation of, or in consultation with which any appointment or promotion, as may be prescribed, is made.