all of them. some kind of uopocalypse that removes every single monster, animal, and blue-named npc from the game. pets in stables aren't affected, so they'll instantly become a commodity; and so will all the different kinds of loot that are now temporarily unavailable because the monsters they spawned on are gone. this will completely rock the economy. leave the world entirely empty of spawns for a week and let the players sort out the resulting chaos. then slowly start reintroducing the fauna through a series of player quests to bring the life back to sosaria. that is my idea for the afternoon