Minecraft wiki entry for Before_Village_%26_Pillage, associated text: Careers were assigned to each villager as they spawned, with multiple careers being part of the same profession, and sharing textures. For example, brown-robed villagers could be fletchers or fishermen and blacksmiths could be armorers or weaponsmiths. These careers were viewable in the trading GUI, but the villager's level was not. Every villager spawned at tier 1 of their given career, which ranged from 2–4 initial unlocked trades (i.e. all shepherds spawned with only two options, buying wool and selling shears). Each tier consisted of a defined set of trade offers, and the tiers were the same for any given career (see the chart below). They could unlock new tiers when an existing offer was traded. Note that the trading GUI had to be closed before a villager would unlock a new tier. When they did, they would receive Regeneration I and become surrounded with purple and green particles for a few seconds. Each career had a fixed sequence of tiers, and would only unlock a finite number of offers.