1. Treasure Class (TC) vs. Monster Level (mlvl) Two-Step Roll
Every equipment drop in Diablo 2 Resurrected resolves in two stages: first, the monster's Treasure Class (TC) must reach the base item's equipment tier (e.g., TC 87 for Diadem or Sacred Armor). Second, the monster's level (mlvl) must meet or exceed the Unique/Set item's Quality Level (qlvl). If TC is sufficient but mlvl is lower than qlvl, the item drops as a failed double-durability Rare instead.