except in cases of promotions to Class I posts carrying higher pay scale, which was to be made on the merit-cum-seniority. The plea raised by the writ petitioners is fundamentally that on completion of the requisite service, they were eligible for consideration for promotion to the post of Lecturer or Headmaster, Middle School, but such eligibility for promotion was curtailed by the prescription of departmental limited examination through the 2008 Rules. The authority to make 2008 Rules in supersession of 2003 Rules in exercise of power under Article 309 of the Constitution of India, is not and cannot be, disputed. The Establishment is well within the authority to recast the modality of appointment to higher cadres, including where promotion is the method of appointment. No case of any hostile discrimination has been made out. The yearning or aspiration of a person in service to promotion under the 2003 Rules is not something that amounts to unsurmountable legitimate expectation eligible to be reckoned as a crystallised right in terms of the Constitution that would invalidate the 2008 Rules on any principle relating to validity. The plea of the Petitioners on this count, therefore fails.