The popular kids would get all the attention from teachers.The athletes would be given games to play that favor their abilities.
The lunch lady would only serve food that she wouldn't eat.
The smart kids would be made to look dumb. They would be constantly outwitted by older kids that were asked to come back to boost the average scores. Those outwitted would be sent to Remedial island where they would have to repeat their lessons until they get it right and then only one would return to regular classes.
If you find an exam idol, you are allowed to skip classes until the end of the year. Finally, only the one that is the most liked gets to graduate.