No, yes, but, no but, Here goes:
Base item Quality levels (Qlvl) and Treasure Class (TC) basics1. Every item has a Qlvl (Quality level) for the base item. These are set by the game definitions.
2. The base item Qlvl's are used by the game to classify which TC (Treasure class) it belongs to.
3. TC's are from 3 to 87 in steps of 3.
4. Each TC contains all items with a Qlvl <= the TC. Ie, TC 3 contains all items with a Qlvl of 1-3, TC 6 contains all items with a Qlvl of 4-6 etc.
5. Each TC also contains all TC's with a lower number, meaning TC 87 contains all items.
6.
Important! TC's ONLY relates to base items. Take this on trust for now and read on.Monster TC's 1. All normal monsters drop from the TC <= their monster level (mlvl). Mlvl = area level (alvl).
2. Champions have mlvl = alvl +2, random bosses and minnions are mlvl = alvl +3
3. Superuniques and Act bosses have predefined TC's which are unrelated to their mlvl.
TC's for Uniques and set items1. The TC for a unique or set item is the same as the TC for a cracked version. Always.
2. However, set items and unique items also have one additional restriction. This is an individual qlvl (note the smal q
).
3. This qlvl is the same for an entire set, whereas each individual unique item has a qlvl set in the game item code.
3. Note that the qlvl can be greater, lesser or equal to the Qlvl of the base item.
4.
The qlvl does not determine which TC the item goes into, but it determines the minimum monster level required to drop it.5. This only causes a problem where a monster has the required TC to generate the base item, but NOT the required mlvl to drop the unique. A well known example is Pindleskin. He drops from TC 87 (defined by the game as he is a super unique monster), but he is only mlvl 86. Even though he drops from the highest possible TC in the game, he is unable to generate the three uniques that have a qlvl of 87. (Azurewrath, Tyreal's Might and Arachnid Mesh). Arachnid is actually a good example here as it is actually in TC 63 (Spiderweb Sash base item is Qlvl 61). Lots of monsters can drop the base item but cannot drop the unique version because it requires mlvl 87.
6. When the quality roll passes, but the mlvl is not high enough to drop the unique or set version, the game drops a trippel durability rare item instead of the unique (failed unique), or a double durability magic item instead of the set item(failed set). This also happens if the quality roll passes but there is NO applicable unique or set item to pick at all.
The only part of any of this that is influenced by MF% is the roll on the base item drop to see if it's Unique / set / rare / magic. ALL items have exactly the same chance of being upgraded once selected. The base item selection is completely independent.
@LifeAintFair - The game only knows quality as Unique / Set / rare / magic etc. It does not "know" that a CoA is better than a Pelta Lunata or Biggins Bonnet. To the game they are the same quality.
Perfect.
But what about lightsaber and azurewrath? Or what about templars might and tyreals might? Or Stormlash and Horizon's Tornado?