Tiers refer to the base level of difficulty of a mission (Low, Medium, High, Very High, Extreme) and its level of boosts and equipment dropped, outside of Exotic equipment from bosses.
Exotics are not confined by Tiers.
|Tier Level:||Mission Level:|
Mission's difficulty directly corresponds with the tier level of loot dropped within it. Elite versions drop the same loot as the non-elite versions, but the difficulty shown is that of the next tier level up.
For example, Fire Forest, a low difficulty level mission, would only drop tier level 1 loot. Elite Fire Forest, which still drops tier level 1 loot like non-elite Fire Forest does, is considered to be a Medium difficulty level mission, the same difficulty level given to Fungus Cave and Vanquished.