PvP Power

PvP Power is an attribute found on pre-Warlords of Draenor gear that increases damage dealt and healing done to other players in PvP situations. It is the counterpart of PvP Resilience, which reduces incoming damage from players. PvP Power can be found on PvP-focused weapons and armor, and can also be added through enchantments and gems. PvP Power is part of the combat rating system.

Described as "a stat on PvP gear to allow PvP gear to be better than the ilvl it shows", PvP Power is not included in items' item level 'budgets', allowing PvP gear to provide additional bonuses for players in PvP compared to non-PvP gear of the same item level. This includes items scaled down by the PvP item level cap. Note that PvP power is only beneficial when attacking other players. For attacking monsters and bosses, attack power and spell power are the desired stats.

With Warlords of Draenor, substantial changes such as the introduction of alternate PvP item levels made PvP Power no longer necessary as a means of empowering PvP gear in PvP situations. As a result, it is not found on gear from Warlords onwards.

Damage

 * 1% extra damage requires 400 PvP Power.

Healing
PvP Power's bonus to healing is based on class and specialization:
 * Healing specializations receive a 100% bonus to healing from PvP Power.
 * Damage specializations for druids, monks, paladins, priests, and shaman receive a 70% bonus to healing from PvP Power.
 * All other specializations and classes (including tanking) receive a 40% bonus to healing from PvP Power.

Official explanation
From the "Dev Watercooler – Mists of Pandaria Stat Changes" blog post:


 * If you have a lot of Power, you'll do more damage to other players, but they likely have Resilience as well. If you fight players in lots of PvE gear, they'll take more damage. Likewise, a player in PvE gear won’t have enough Power to effectively penetrate your Resilience.
 * PvP gear will be lower in item level than PvE gear of an equivalent tier, however the Power and Resilience stats will make sure that PvP gear is more powerful in PvP (both offensively and defensively) than PvE gear. In our budgeting system, the PvP stats will be free rather than causing other stats, such as Strength or haste, to be smaller as a result of including Power or Resilience.
 * The goal of this change is to make it easier for a PvP player to participate in PvE, or for a PvE player to get started in PvP. Currently, we feel it is too large a barrier to go from one to the other, and the result has been that we see more and more players choosing to focus exclusively on only PvP or PvE. In earlier expansions, it was more feasible to use PvE gear in Arenas or Battlegrounds until you acquired the more useful PvP gear. The same was true of being able to use your PvP gear in a dungeon or raid until you acquired something better. In Cataclysm, stepping into PvP with no PvP gear would result in a player being so ineffective that it was difficult to even make progress towards acquiring PvP gear.
 * For the higher-end of PvP or PvE (say Gladiators or heroic raiders), we believe those players will still gravitate towards the dedicated PvP or PvE gear. It is the players who are working towards those two end games that will benefit more from some cross over.


 * PvP Power will not work in instances but does work in the world.

Patch 5.3 brought significant changes to PvP in general, and several changes to PvP Power:


 * The design intent on PvP Power was to allow us to have a stat on PvP gear to allow PvP gear to be better than the ilvl it showed. The intent was not to make it the one and only stat that PvPers want.


 * PvP Power as they were budgeted was strong, so it was easy to take a PvE piece and gem it and make it the BIS piece. We wanted to avoid that, something players really wanted. In terms of the stat concern we changed it from 265 pvp power for 1% to 400 pvp power for 1%. That was a point where a fully geared pvp player had 60% more damage. A common complaint is that the fully geared guy is really exploding the people that’s 1 tier behind it. We just thought this was really an opportunity to change this, adjust the gap a little bit, reduce damage a little in PvP and make the experience better.