Once a clan chooses to proclaim their wealth, the enemy will attempt to construct a siege camp nearby. The base difficulty of the purge is determined by the value of the treasure hoard, although the number of defenders participating may also cause the difficulty to increase. Once a Treasure Coffer has a treasure value, a purge can be called on the Treasure Coffer's location by interacting with the bookkeeper and selecting Proclaim Wealth. The following is a list of all treasure items available: Inventory loot that can be placed inside the Treasure Coffer, and Small or Heroic Treasure that can be placed in the area around the Treasure Coffer. There are three different types of treasure. Once placed, the Treasure Coffer creates a 'treasure room' around it with a spherical radius of approximately 7.4 foundation blocks. The central object of a purge is the Treasure Coffer, which serves to determine the purge's difficulty, is used to start purges, and is the ultimate target of the purge.
