The Disciple

[adeyke]

And I would assume that since the Disciple and Tal's amulet are 'non-normal' set items, that the chances of them being rolled are skewed lower than the chances for the other, 'normal' set amulets. adeyke, Ruvanal, or the other code readers would know for sure.

I'm not a code reader. I'm just a tester and MPQ text file reader. That said...

Associated with every unique/set item is a minimum ilvl necessary to spawn (also known as the unique/set qlvl or just level) and a rarity. Whenever the game wants to spawn a unique/set item, it randomly picks from those for whom the ilvl is sufficiently, weighted by the rarity. In the case of set amulets, the data are as follows:

Name_________________________rarity_____level_____best chance_______final chance
Civerb's Icon________________7__________13________7/ 7 = 100.0%_____7/45 = 15.6%
Cathan's Sigil_______________7__________15________7/14 =__50.0%_____7/45 = 15.6%
Angelic Wings________________7__________17________7/21 =__33.3%_____7/45 = 15.6%
Vidala's Snare_______________7__________19________7/28 =__25.0%_____7/45 = 15.6%
Arcanna's Sign_______________1__________20________1/29 = __3.4%_____1/45 =__2.2%
Iratha's Collar______________7__________21________7/36 =__19.4%_____7/45 = 15.6%
Tal Rasha's Adjudication_____1__________26________1/37 = __2.7%_____1/45 =__2.2%
Tancred's Weird______________7__________27________7/44 =__15.9%_____7/45 = 15.6%
Telling of Beads_____________1__________39________1/45 = __2.2%_____1/45 =__2.2%

The first chance is the chance at the optimal ilvl. For example, at ilvl 13-14 for Civerb and ilvl 26 for Tal Rasha. The second chance is for ilvl 39+, when all amulets are available. As you can see, at ilvl 39+, some amulets are 7 times as likely as others, and, since the Disciple amulet starts appearing the latest, it can be considered the rarest.