- Always spawn in the same location.
- Only Griswold, Radament and Nihlathak receive randomly selected Unique bonuses in Nightmare and Hell (Putrid Defilers are treated as normal Unique monsters).
- Slow Missiles does not apply.
- -% Defense from Cloak of Shadows is not applied.
- Ignore Target's Defense only applies to minions.
- -% Target Defense is only 50% effective, but still 100% effective against minions.
- Freeze length chills instead; only minions can be frozen.
- Stun length does not apply.
- Effects altering AI cannot be applied directly, but can affect minions (although Putrid Defiler minions are also classed as bosses).
- Life lost to Crushing Blow is halved (so 1/8 of current base life when applied by a melee attack and 1/16 when applied by a ranged attack).
- Life drained by Open Wounds is halved.
- Sanctuary does not knock back or apply its radial Magic Damage to undead bosses Griswold or Radament.