WoW Priest PVP Guide
Priests often find themselves filling a healing role in World of Warcraft. The expectation from other players is the same whether a priest is engaging in player versus environment (PvE) or player versus player (PvP) combat. Priests are a powerful healing force in both PvP and PvE situations, but they lose a great deal of their power if they focus only on healing in PvP.
Unlike the shaman or the druid, the priest is a pure caster, but a priest must be able to adapt to rapidly changing situations when he fights other players.
Priest PvP Strengths
The shadow branch of the priest talent tree is usually considered to be the best one for players who engage in PvP. It allows the priest to do decent damage and at higher levels gives the priest access to shadow form. According to WoW Wiki, when this spell is combined with another priest armor increasing spell, inner fire, the damage absorption of a priest is equivalent to the damage absorption rate of characters wearing mail armor.
The good news is that priests, especially shadow priests, should have high resistance to shadow spells which will cause little problems when facing warlocks. At higher levels, priests get access to high damage instant cast spells. The advantage of instant cast spells in PvP over spells with a casting time is that World of Watercraft's programming checks for line of site when the button is pressed, not afterwards.
Priest PvP Spells and Tips
Many World of Warcraft players set up key bars for different situations. A priest who sets up a bar for PvP situations, or any class for that matter, will find his most useful abilities available at the stroke of a key. For priests, the most useful spells are the fears, shadow form if the priest specializes is shadow specialized, mind blast, and mind flay, and one or two heals. One of these hot-keyed heal spells should be the heal over time spell that is instant cast.
Holy priests are at a disadvantage in single player PvP situations as opposing players will take the priest out first. His team mates should help keep the holy priest alive, but spells like Power Word: Shield helps prevent a priest who has specialized in healing from taking a dirt nap. Discipline priests have a similar problem, but they have more flexibility and buffs enhanced by discipline talents give the priest more armor and hit points.
Priest PvP Gear
In many mmorpgs, including World of Warcraft, gear that may be desireable for PvE does not always work as well in PvP situations. In grouping situations, a shadow, discipline, or holy priest will attempt maximize his mana pool, his spirit regeneration, and if possible items that add spell damager or make heal spells more effective.
The larger mana pool from int is still viable in PvP, but the fights are shorter than they would be in a raid or instance. Spirit becomes less important for mana regeneration, and all classes including priests should start to seek stamina gear.
Word count limitations prevent me from suggesting tactics on dealing with each class individually, but this guide should give the player a starting point that he can build on in World of Warcraft's battlegrounds or arenas.