**Before I begin, this move might be very 'dirty', but it's not because we want to screw up schools.
Scenario: say you got accepted to school
X, but honestly school
Y is your top choice yet you didn't get accepted to it.
Ok, you decide to accept school
X's offer, telling yourself that a bird in the hand is worth two in the bush.
After accepting school
X's offer, you plan to defer your admission for a year, which is considered pretty normal.
But your plan is to take that year off to re-apply to school
Y: re-taking the GMAT, maybe improving your resume, getting a related job, etc..
So, during that year you do all of the previously mentioned actions and re-apply to school
Y. Eventually, school
Y accepts your offer.
How 'damaging', 'unacceptable', 'wrong', is it to accept an offer from a school, defer your admissions for a year, and during that time to re-apply to another school, get accepted to it, and tell school
X that you won't attend it eventually?