Acquiring stamps in Sulfur requires completing fetch errands for friendly world characters and spending this specialized reward currency with merchant Arthur for sanctuary upgrades.
Introduced as part of the quest system, stamps provide a permanent reward structure for helping non-player characters throughout the game. Various allies across the church and exploration zones—such as Ralphie, Stefle, the Gravekeeper, and the Hawland marketeer—present tasks requesting specific finds. Errand objectives frequently involve delivering bodily organs, medical anomalies like kidney stones, or accessories like sunglasses. Handing over these requested objects completes the task and rewards players with stamps.
Players can spend their accumulated stamps by visiting Arthur at the church. Arthur operates as a dedicated trader offering inventory selections scaled to your stamp savings. Among his inventory, players can unlock the ammo box dispenser to buy munitions in bulk using spare gold. Arthur also supplies a station that takes all the weapons you have that are enchanted and removes their enchantments when modifications turn out unfavorable.