How do rune drops work? They have their own TC?

[:1]Nvm.

Any area level 81+ can drop zod.|||Runes are organized in separate treasure classes, independently from armor and weapons.

With respect to random monsters and bosses, those with the same monster level can generally drop the same stuff, with a few exceptions, like archers having a greater chance to drop bows and ghosts being unable to drop armor and weapons - thus having a greater chance for all the rest, including runes!

Act bosses and superuniques are special. Their TC selection is different from the TC selection of the mosters around them, often (but not always) being lower.|||So can any regular monster above 81 should be able to drop up to zod? Is there a chart?|||When thinking about it, cows might be a bit special. Their chance to drop HRs is rather high in comparison to other monsters.

ATMA (single player muling program) has a drop calculator for this purpose. It hasn't been updated since 1.11, so you will have to replace a few data files in order to have proper rune drop chances. There should be more information about it in the single player forum.|||I think Hell cows, Baal, and Worldstone Keep have the best chance of dropping Zods, could be wrong though