Priest Healing Stats

So, how good are really items that have +Healing Spells?� Should a healing character choose an item that is +63 Healing Spells over one that gives +15 Int?

This document sets out to find some basis for making those choices.� It assumes that the one thing the character wants to be good at is healing, and that other abilities do not make a big difference when choosing equipment.� The calculations are based on a level 60 healing-specced priest who is assumed to have 6000 mana points.

If you can�t be bothered to ready the thing, I can reveal my conclusion: Based on my own playing style, the +Healing Spells bonus must be >3.8 times higher than the +Int bonus for me to pick the +Healing item.

How +Healing items work

Here is the explanation from Blizzard on how +healing items work [edited for focus only on healing items]:

There is some confusion about how these effects work and how effective they are, so I wanted to explain what they do.

When an item has the effect "Increases healing done by magical spells and effects by up to 20", the hit points healed by one of your spells will be increased by a fixed amount up to 20. The actual amount that the spell is increased by is not determined randomly, but by which spell you are casting. You are not receiving a random bonus value between 1 and 20 whenever you cast a spell. Some random items, such as those with the property "of Healing", indicate that they provide "+X Healing Spells". The actual amount of the bonus is again determined by the spell being cast. There are a few items that do provide a random bonus, such as Dreamweave Gloves, but their effect notes the randomness by stating that item's bonus as "up to 1 to 19." Once again, the bonus received could be reduced depending on the spell being cast.

Spells with longer casting times such as Greater Heal will receive the full bonus listed every time they cast the spell. Spells with instant or short cast times receive a fraction of the bonus listed. As an example of such a spell, Flash Heal (Rank 7) only receives approximately 43% of the item bonus. Talents or other effects that might change the casting time of the spell will not change the bonus; the amount received is a property of the spell being cast.

Most long duration Heal over time spells have the bonus divided amongst every tick. So Renew, which lasts 15 seconds and heals an amount every 3 seconds, has 20% of the bonus applied each tick. In a similar fashion, channeled spells also have the item bonus divided amongst every tick of the spell's duration.

Lower level spells receive a greatly reduced benefit from these effects.

These effects all stack. So if a Priest is wearing 3 items that provide up to +20 Healing Spells, you will have a combined +60 to Healing Spells. This means every high level Greater Heal cast will heal an extra 60 hit points.

These bonuses are also added to the effect of the spell before the 50% bonus from a critical spell hit is applied.

Note that there is currently a bug in the game that affects heals over time such as Renew and Rejuvenation. The +healing items worn by the caster are only providing the appropriate healing bonus if the caster is also the target of the spell. Direct heals such as Greater Heal work fine, and the +Healing bonuses are being appropriately applied. We're working to fix this bug, but currently I can not provide any kind of ETA on the fix. [The patch note for 1.4 stated: �Effects that indicated that they increased damage and healing by all magical spells were actually not improving healing. They now will properly increase healing by the listed the amount.�.� It is unclear to me whether or not this refers to the bug discussed here, but I will assume in the document that it has been fixed.]

In another post, Blizzard clarified that to get the full bonus, a direct heal spell must have a casting time of at least 3.5 seconds.� Thus, the Priest healing spells get the following bonus factors:

Greater heal: ��������������� 1.000

Flash Heal:������������������ 0.429

Prayer of Healing:�������� 0.857

Although not stated unambiguously, it seems that Renew gets the full effect (but spread out evenly over the spells duration).

The basis for comparison

I want to compare +Int and +Healing items on two parameters that are important to a healer:

�      Hit points healed per full mana bar (hpmb)

�      Hit points healed per second (hps)

Hpmb determines how many hit points the priest can heal before he must announce �oom� and tell his party to start quaffing their healing potions.� This is arguably the most important measure of how good a healer the priest is. �Hps determines the speed at which the priest can spew out hit points, which is also important in fights with high-damage mobs and not quite enough healers in the group.

Here is a table created by Whispre and Amentet and published in their excellent Priest Guide on Allakhazam.com (Table 1).� I have added a column for Hpmb and added accuracy to the hps column.

Table 1. Healing spell effects with healing spec and without +healing items

�Talents applied� refers to talents that affect the stats in this table.� These are the talents that in this document are referred to as a �healing spec�. These are: MA = Mental Agility, IR = Improved Renew, SH = Spiritual Healing, IH = Improved Healing, MH = Master Healer, IPH = Improved Prayer of Healing

The effect of +100 Int

I will calculate using large bonuses, to avoid rounding errors.

Getting +100 Int increases the Priest�s mana bar to 7500, and it improves the chance of getting critical heals by 1%.

The effect of the extra mana is straightforward � it increases hpmb by 25.0% and does not affect hps at all.

The effect of the extra crit chance is to increase the average heal of each spell by 0.5%. This increases both hpmb and hps by 0.5%.

So, to summarize the effect of +100 Int:

�      +25.5% hpmb

�      +0.5% hps (although this does not apply to Pw:S)

The effect of +100 Healing Spells

+100 Healing Spells simply impacts the �hit points� part of the ratios.� All we have to work out is how many percentage points that effect is for each spell:

Table 2. The percentage effect of +100 Healing Spells

Evidently, the value of +Healing Spells depends quite a bit on the casting habits of the priest.

To try complete the analysis, we must make assumptions about the �spell mix� that the priest casts.� This totally depends on playing style, but I must choose something. I assume the following (Table 3):

Table 3. Casting mix (share of spells cast)

Based on this, I calculate the following average effects of +100 Healing Spells:

�      +5.3% hpmb

�      +4.3% hps

Summing it all up

In summary, these are the effects of +100 Int and +100 Healing Spells respectively (Table 4):

Table 4. Comparison of +100 Int and +100 Healing Spells

This table is inconclusive, because deciding between +Int and +Healing Spells depends a lot on what you value � hpmb or hps.� The conclusions can be as follows:

�      It might be interesting to have two sets of equipment � one hps set and one hpmb set.

�      An item with +5 Healing Spells will always be better than an item with +1 Int

�      An item with +10 Int will always be better than an item with +1 Healing Spells

One way to reach a definite conclusion is to assign importance to hps and hpmb respectively.� Again, this is about playing style and the encounters you expect.� Personally, I think that hpmb is significantly more important than hps.� I�ve seen much more wipes in oom situations than in situations where my healing simply couldn�t keep up.� So I would assign 75% importance to hpmb and 25% importance to hps.

On this basis I score the two alternatives on �weighted average percentage improvement� for the comparison (Table 5):

Table 5. Comparison of +100 Int and +100 Healing Spells � scoring

Conclusion: +Int is approx. 3.8 times better than +Healing Spells.� This means that I would choose an item with +Healing Spells only if the bonus was about 4 times better than the stat bonus of the +Int item.

A final comment: Some items have a random +Healing effect (see the example of Dreamweave Gloves in the Blizzard quote above).� To compare these with +Int, take the mid-point of their range.� For example, the mid-point for Dreamweave Gloves if 10 (mid-way between 1 and 19).� Therefore, they are comparable to +10 Healing Spells items.