Prayer of Healing

Prayer of Healing is the main priest AoE healing spell. It heals party members within 30 yards of the friendly target for a small amount. It is learned at level 44 for.

Notes and tips

 * Prayer of Healing has a spell power coefficient of 40% per target.
 * An additional benefit to using an AoE heal such as Prayer of Healing, rather than healing multiple targets individually, is the convenience and lack of time lost selecting each target. AoE healing may therefore be preferred even when not the most mana efficient option.
 * As Prayer of Healing only heals for a small amount, it is useful for avoiding overheals (and so conserving mana) when multiple targets need 'topping up'.
 * When the targets will not survive long enough to allow Prayer of Healing to be cast, Holy priests can cast Circle of Healing - as well as being instant cast it offers a significantly higher HPS. The priest can then follow up with Prayer of Healing.
 * Without improvements, Circle of Healing and Prayer of Healing are roughly equal in terms of mana efficiency. However Circle of Healing is far faster, and has a 10 second cooldown.
 * While Prayer of Healing only has a healing radius of 30 yards, it has a cast range of 40 yards.
 * The area of effect is centered on the target, not on you, so it can heal players up to 70 yards away from you. This allows you to heal players that would otherwise be out of reach.
 * Line of sight is only checked on the target, not on other players receiving the healing. This is useful in arenas and if a boss locks you out of its room. In such situations, cast it on yourself.
 * Prayer of Healing can be used in conjunction with Inner Focus, removing its mana cost and increasing its crit chance by 25%.

Improvements
Holy talents: Discipline talents:
 * Glyph of Prayer of Healing adds a HoT onto the spell, healing all affected targets with an additional 20% of the initial heal over 6 seconds.
 * The Chakra state Chakra: Sanctuary increases healing done by all AoE spells by 15%.
 * Serendipity potentially reduces the cast time of Prayer of Healing by 20% and its mana cost by 10%.
 * When Inspiration is talented, healing crits will grant the target a temporary 10% physical damage reduction buff. Repeatedly casting small AoE spells (rather than healing targets individually) is far more likely to proc this effect due to the greater number of chances for a crit to occur.
 * Divine Aegis causes crits and all heals from Prayer of Healing to create a protective shield on the target, absorbing 10/20/30% of the amount healed, lasting 15 seconds.
 * The Discipline Mastery Shield Discipline increases the absorb effects produced by Divine Aegis by 20%, and an additional 2.5% per point of Mastery, significantly increasing their contribution to Prayer of Healing.

Numbers
Like all AoE healing spells, Prayer of Healing's mana efficiency depends upon the number of targets healed. Only when sufficient numbers of players are in need of healing does the spell become an efficient option, and this number varies significantly depending on the priest's talents, stats, etc.

Not only talents affecting PoH are involved in this calculation; talents affecting direct heal options such as Flash Heal and Greater Heal, by improving these abilities, effectively increase the number of targets required to make PoH the best option. Talents that add additional effects to direct heals (such as Surge of Light or Strength of Soul) may further incline the priest to heal targets individually with these spells even when PoH would be a more mana efficient option. Conversely, the convenience of AoE healing spells may incline a priest to use a spell such as PoH even when it is less mana efficient. The notes below should therefore be taken as a rough guide.

As a rule of thumb, with no related improvements, PoH requires 3 targets in order to become one of the most mana efficient options (equal with Heal). However many healing-oriented priests will choose to spend points in Empowered Healing. By improving the priest's other healing options, this increases the number of targets required to 4. With Glyph of Prayer of Healing or other substantial improvements (or combinations thereof) only 3 targets are required for this to occur, even with Empowered Healing.

Without Empowered Healing:
 * PoH requires 3 targets in order to become one of the most mana efficient options. With 2 targets, it is about as efficient as Flash Heal, but much slower.
 * With Divine Aegis, and either Glyph of Prayer of Healing or sufficient points in the Discipline Mastery Shield Discipline, only 2 targets are required to make PoH the most efficient option.

With Empowered Healing:
 * PoH requires 4 targets in order to become the most mana efficient option. With 3 targets it is around 3% less efficient than Greater Heal.
 * With Chakra: Sanctuary or Serendipity in place, PoH requires 3 targets to become one of the most mana efficient options (equal with Heal), and with 4 targets is significantly more efficient.
 * With either Glyph of Prayer of Healing, Chakra: Sanctuary and Serendipity, or 2 or more points in Divine Aegis (counting the shield as equivalent to a heal), only 3 targets are required in order for PoH to become the most mana efficient option.
 * Any combination of the above improvements will render PoH even more mana efficient, as well as time efficient.

In practice the time efficiency (HPS) and convenience of using Prayer of Healing will cause many priests to use it even when it is not one of the most mana efficient options. When Prayer of Healing is the most mana efficient option, it makes sense to use it even when time is not a factor.