Returns the threshold used for Master Looter, Group Loot, and Need Before Greed loot methods. Items above the threshold quality will trigger the special behavior of the current loot method: for Group Loot and Need Before Greed, rolling will automatically begin once a group member loots the corpse or object holding the item; for Master Loot, the item will be invisible to all but the loot master tasked with assigning the loot.