Your attacks with maces ignore up to X% of your opponent's armor.
The mace is a very symbolic weapon, often chosen by paladins and shamans as a potent and extremely functional talisman of justice, representing a certain weight of authority.
To the professional soldier however, it is a different sort of weight, and how best to apply it, that matters, and if used properly, this adaptation of the simple carpenter's hammer can shatter bones and rupture internal organs, but the real mastery comes in the hidden finesse of knowing exactly where to hit.
The inherent symbolism and humble origins of the mace tend to appeal to humans the most...
Mace Specialization gives rogues passive ignore armor while wielding a mace. This effect increases by 3% with each talent point.
/Patch 3.0.2 (14-Oct-2008): No longer stuns enemies, now ignores 3/6/9/12/15% of target's armor.
Patch 1.7.0 (13-Sep-2005): The stun effect can now be resisted.