Curse

The following may also overwrite Necromancer Curses:
Only one curse at a time can be active on a target; when a different curse is cast on a target that has already been cursed, it will normally overwrite the previous one. There are a few exceptions: [1]
- Grim Ward can only be overwritten by Confuse and Attract
- Fleeing effects have their own hierarchy; those higher on the following list cannot be overwritten by those lower:
1. Grim Ward
2. Terror
3. Hit Causes Monster to Flee %
4. Howl
- Confuse cannot overwrite itself or be overwritten by any of the following:
  - Dim Vision
  - Terror
  - Attract
  - Taunt
  - Grim Ward
  - Hit Blinds Target
- Attract cannot be overwritten by anything, including itself.
When the same curse is cast on a target, it will normally overwrite the previous one if the skill level is equal or greater. The exceptions are Confuse, Attract, Howl and Cloak of Shadows, which cannot overwrite themselves and must expire before they can be cast on the same target again (although in the case of Cloak of Shadows, only when cast by the same player). [2]

Cannot be Cursed

Act	Monsters
I	Foul Crow Nests; Gargoyle Traps
II	Mummy Sarcophagi; Black Raptor Nests; Sand Maggot and Rock Worm Eggs; Sand Maggot Queen; Fire Towers; Lightning Spires
III	Giant Lamprey Eggs; River, Water and Stygian Watchers
IV	Trapped Souls; Windows; Blood Maggot Eggs; Bone Prisons
V	Catapults; Evil Demon Huts; Barricades; Barricaded Towers and Doors; Prison Doors; Blood Maggot Eggs; Festering Appendages