I would like to know if global server wide switches and variables would be possible and how difficult it would be to implement.

My goal is to have quests, mobs or NPC’s that will complete an action once then the server switch is flipped and no one, not even new players just starting the game, will be able to complete the same quest or action again.

Global variables would also be another nice feature to have, It could create possibilities for adding some strategy gaming elements.

So is it possible with this engine? What level of complexity does it have to implement such a feature?