Minecraft wiki entry for Armor_farming, associated text: The first way of getting large quantities of emeralds is to build a redstone farm which a villager will buy for cheap, and continuously trade that same item to multiple villagers of that profession. To do this you will need to trap multiple villagers inside of an area with a profession block in front of them (whichever villager trades the item you are making a redstone farm for) so that their profession changes to the villager of your choosing. Once you have an ample amount of them (4-6) you will also want to gather 4-6 armorer villagers so that you can farm the armor more easily. The armorer's profession block is a blast furnace. Once you have done this, start working on contructing a redstone farm. Some farms that are very profitable in emeralds are: