Hammer of the Righteous is a paladin ability learned at level 20 for those with either the Protection or Retribution specialization. It allows paladins to strike a target, but then have a wave of holy damage sweep over all other targets within range while generating a charge of holy power.
It attacks the paladin's current target with a straight melee physical attack, doing a percentage of weapon damage.
If the physical attack connects with its target, it then attacks all nearby enemies (including the paladin's target) with a Holy damage spell. This is resolved as a spell attack, using the paladin's spell miss chance.
Patch 6.0.2 (14-October-2014): Hammer of the Righteous now deals 50% Physical weapon damage (up from 15%) to the primary target, but the primary target is no longer hit with the Holy damage.
Patch 4.2.0 (2011-06-28): Hammer of the Righteous mana cost has been lowered to 10%, down from 12% to match Crusader Strike.
Patch 4.0.6 (8-Feb-2011): Crusader Strike, Holy Shock, and Hammer of the Righteous no longer incorrectly grant Holy Power from a missed attack.
/Patch 4.0.1 (12-Oct-2010): Cooldown reduced from 6 seconds to 3 seconds, now hits target for physical damage and all nearby enemies (including target) for holy damage, and gives 1 Holy Power.
Patch 3.1.0 (14-Apr-2009): Now does correct damage with heirloom weapons.
Patch 3.0.3 (04-Nov-2008): Tooltip corrected to indicate it does 4 times weapon DPS instead of 3.