Mace Stun Specialization is categorized as an "uncontrollable" stun, i.e. random. It shares diminishing returns with all other stuns of this nature including, but not limited to the Mace Specialization for rogues. It doesn't share any returns with moves such as Cheap Shot or Intercept, etc. (those would be classified as controllable stuns).
Here's a few examples of moves which will share diminishing returns under controllable stun:
- Charge (warrior)
- Intercept (warrior)
- Concussion Blow (warrior)
- Cheap Shot (rogue)
- Bash (druid)
Note: Kidney Shot (rogue) does not share diminishing returns with any ability to my knowledge (this is a category unto itself).
Edited, Jul 25th 2008 8:20pm by Arideni