Though it is settled law that the Rules applicable in matters of determination of pension are those which are in force at the time of retirement, but, held, that does not mean that employer can depart from this principle arbitrarily and confer benefit of Rules in force at the time of appointment, for computation of pension upon one employee and deny the same benefit to another employee who is similarly situated.
[G. Sadasivan Nair v. Cochin University of Science & Technology, (2022) 4 SCC 404]