Archive for b. Mana Regen Mechanics


Innervate – lvl 40   Increases the target’s Spirit based mana regeneration by 400% and allows full mana regeneration while casting. Lasts 20 sec.
30 yd range, Instant, 6 min cooldown


  • 5 times more normal regen from spirit
  • mana regen will act outside of the FSR for the duration of Innervate. This means continue to cast and still get 100% of the mana from Innervate.

Raaff’s Mana Regen Calculator *BETA

Innervate Guidelines

Spirit vs. Mana/5

Spirit vs. Mana/5 Revisited – Accounting for Innervate

Which Is Better?

Formula for mana gained while under Innervate is as follows:

 Mana = [((Spirit/4.5) + 15)*50] + (4 * Mp5)

Therefore we can calculate the size of your self-innervates if we know your total spirit:

Total Spirit Mana Restored Under Innervate
100 1861
150 2416
200 2972
250 3527
300 4083
350 4683
400 5194
450 5749
500 6305
550 6860
600 7417
650 7972
700 8528

Innervate gains nothing from mana/5, but because it’s a 20-second cast, we assume that you’ll get back 20 seconds worth of your mp5 regen (which is 4 * mp5), so that’s why we add this to the “mana gained while under innervate.”

Note that when you cursor over the “Regen” section of your character screen, the “Regeneration While Casting” shows your Mana/5 plus 30% of your spirit regen (because you have 3/3 Intensity). This number is NOT your actual mp5 (you’ll just have to tally this up manually).

All of this math helps us use Innervate more effectively.

Innervate Guidelines

  1. Innervate a target who has a significant amount of spirit. Priests are the usually the best, followed by druids; however, realize that this depends on how much spirit gear your target has. Shaman and Paladins usually have very low spirit, so Innverating them is almost a waste of a cooldown. If you had to pick one, I would probably choose the shaman.
  2. Innervating a shadow priest is often beneficial for the group as a whole because shadow priests burn through mana very quickly, but return mana to the entire group. Therefore, helping a shadowpriest with mana will allow them to dps more aggressively, which will be better for that entire group in the long run.
  3. Innervate early on very long endurance fights – Magtheridon and A’lar. About a minute into the fight, innervate someone who is at like 50-60% mana. You’ll probably waste a few innervate ticks, but you’ll also get your Innervate back a second time towards the end of the fight.
  4. When self-innervating a lot of druids throw on weapons with a ton of spirit on them (and with +spirit enchants) to maximize the mana gained from innervate. See General Gear Recommendations for a few examples.

Spirit vs. Mana/5

While not in the FSR (while not casting):

  • 4.5 Spirit = 1 mana per tick (every 2 sec)
  • 2.5 Mp5 = 1 mana per tick
  • 1.8 Spirit = 1 Mp5

However, while in the FSR:

  • 15 Spirit = 1 mana per tick
  • 2.5 Mp5 = 1 mana per tick
  • 6 Spirit = 1 Mp5

Raid buffed you’re going to have a Blessing of Kings, and spirit will stack with this, mp5 wont. Also remember that the Living Spirit talent (+15% spirit) will stack with Blessing of Kings. These two buffs will affect the mp5 to spirit conversion:


However, realize that mp5 does absolutely nothing for your innervate, so which is better? Mp5 or Spirit? Before we can answer that question, we need to talk about a little spell called Innervate…

Spirit vs. Mana/5 Revisited – Accounting for Innervate

Which is better? The answer to that question depends on a few conditions:

When all the math is done, here’s the conversions:


Note that we assume Innervate returns mana based on a 6-minute cooldown.

Also, note that we use the phrase “Spirit (on a piece of gear).” This means that when you compare gear you can use these conversions directly to determine which will give you more regen. For example, if you have Living Spirit, Blessing of Kings, and you’re trying to compare two pieces of gear (one with 25 spirit, and another with 10 mp5) here’s how you would do the math:

 25 Spirit / 2.46 = 10.16 mp5

Therefore the piece of gear with 25 spirit would have better regen (assuming you innervated yourself).
Here’s an example of the math behind these numbers. In this case we seek to determine the spirit to mp5 conversion if you self-Innervate and if you have Blessing of Kings (but not Living Spirit):

Regen from spirit:

 [(1 Spirit * 1.1)/4.5] x 0.30 = 0.073333 Mana/Tick
 0.073333 Mana/Tick *(5/2) = 0.183333 Mana/5
 1 Spirit = 0.183333 Mana/5

Effective Regen from Innervate:

 [(1 Spirit * 1.1)/4.5] x 50 = 12.222222 Mana/Innervate
 12.222222 Mana/Innervate / 6 Minutes / 12 = 0.169753 Mana/5
 1 Spirit = 0.169753

So adding these up:

 0.183333 Mana/5 + 0.169753 Mana/5 = 0.353086 Mana/5
 1 Spirit = 0.353086 Mana/5
 2.83 Spirit = 1 Mp5

Which Is Better?

Spirit or Mana/5? The truth is that you want a balance of both. Spirit increases the healing from your ToL Buff, and it also increases the size of your self-Innervates. However, even with self-Innervates, even with the +15% spirit talent and Blessing of Kings: Mp5 is still preferable to spirit. Now, that’s not to say that you should shun spirit all-together, no you need a good chuck of spirit too… but pound for pound, point of regen for point of regen, Mp5 is usually superior.

If you can find a piece of gear that has 2.83 times (or 2.46 times) as much spirit as Mp5, then that piece is superior. It depends on your conversion (based on spec), whether you plan to self-innervate (or if you plan to innervate others), and how much +healing you want your ToL bonus to give.

There… I hope that clears up the debate. You can argue both ways ad nauseam, but now you at least have the conversions so that you can select gear more intelligently.

Mana Regeneration


Spirit-based regeneration

The main base stat which regenerates mana is spirit. To a lesser extent, intellect also contributes, and the character level adversely affects regeneration. It’s a good rule of thumb to assume that 1 spi = 1 mp5 while not casting.

 MP5 = 5 * (0.001 + sqrt(Int) * Spirit * Base_Regen) rounded up

Base Regen lvl 80: 0.005575


The above chart was generated using this data. The formula shows that regeneration increases linearly with spirit and with the square root of intellect. The base regeneration goes down as level increases. When analyzing the plot it appears that levels 1-10 have one curve, 11-60 another and 61-70 have a jagged but almost linear decrease which seems to have been tweaked by hand.

Together these design elements seem to enforce balanced stats, so that stacking spirit to the detriment of intellect is to be avoided. It seems that 1 spirit = 1 MP5 was the target of the game designers. A level 70 caster needs about 460 intellect to reach this point.

Five Second Rule

After a character expends mana in casting a spell, the effective amount of mana gained per tick from spirit-based regeneration is reduced (interrupted) for a period of 5 seconds. This is commonly referred to as the five second rule (FSR).
Channeled spells are handled a little differently. The FSR starts when the spell’s channeling starts; i.e. when mana is expended. The interruption continues for at least five seconds, and longer if the channeled takes more than five seconds. For example, Mind Flay channels for 3 seconds and interrupts regeneration for 5 seconds (from the moment the spell cast starts), while Tranquility channels for 10 seconds and interrupts regeneration for the full 10 seconds, but not longer.
By default, the interrupted mana regeneration ratio is 0%. Several effects can increase this ratio, including:

Spells which don’t cost mana do not start the FSR. This includes spells with a normal mana cost of zero (e.g. Nature’s Swiftness), but also spells whose effective cost is reduced to zero by some effect (e.g. by Clearcasting or an item ability or proc like Eye of Gruul).

Effect Interrupted mana regeneration ratio increase
Intensity  10%-30%*
Innervate 100% (and increases mana regeneration to 500%)


Direct regeneration

Many effects increase mana regeneration directly i.e. without increasing spirit. These effects are governed by different rules than spirit-based regeneration, in particular they’re never subject to the five second rule.

The most frequent source of non-spirit-based regeneration is the “regenerates X mana in 5 seconds” stat on items. This stat is usually written abbreviated as “mp5”.

Comparing spirit based and direct regeneration

In theory, direct regeneration is preferable as it is not subject to the FSR. Unfortunately though, mp5 is much harder to get and more “expensive” than spirit. All attributes have an Item Value, a kind of “cost” associated. This value for mp5 is 2.5 times higher than for spirit. For example the two top mana regeneration enchants for chest items yield either 15 spirit or 6 mp5 ([Enchant Chest – Major Spirit] and [Enchant Chest – Restore Mana Prime]) – this shows the factor of 2.5 very clearly.

In order to find out what’s better, characters should first find out their personal time spent inside the FSR, e.g using an addon like Muse or RegenFu. It’s important to perform the measurement under realistic conditions – the time spent inside the FSR while grinding is typically much lower than during a boss fight. Some players actually argue that in a tight situation, it’s safe to assume that the FSR is in effect 100% of the time. It is possible to calculate the percentage of time which has to be spent outside the 5 second rule so that 2.5 points of spirit are more effective than 1 point of mp5. Examples:

Average lvl 70 priest with maxed Meditation: 2.5 spirit return 2.5 mp5 outside the FSR, and 0.75 mp5 inside. The mathematical form of the question is thus

2.5 * x + 0.75 * (1 - x) = 1
1.75 * x = 0.25
x = 0.14

So if that priest spends 14% percent of the time outside the FSR, the enchant with 15 spirit yields a higher regeneration than 6 mp5. If the time inside the rule is 86% or more, 6 mp5 is more efficient.

For lvl 70 characters without spirit regeneration inside the FSR:

2.5 * x = 1
x = 0.4

That is they have to spend 40% of their time outside the rule for spirit to be better than mp5.

MP5 vs Intellect and Spirit – Formulas

The following formulas relate intellect, spirit, and mp5 to mana regen both in and out of FSR in an attempt to help establish a relative value between them depending on your current stats.

Based on the formulas for spirit-based regeneration above…

ManaRegen(Int,Spirit,MP5) = [0.001 + sqrt(Int) * Spirit * 0.005575] * 5 + MP5 ManaRegenCasting(Int,Spirit,MP5) = [0.001 + sqrt(Int) * Spirit * 0.005575] * 5 * Coeff + MP5 where Coeff is the decimal percentage of spirit-based mana regeneration that is allowed to continue while casting

The mana regen benefit per 1 point increase of Spirit, Intellect, or Mana/5 can be calculated as…

While not casting:
 NC_RegenPerInt = 0.027875 * Spirit * [sqrt(Int+1) - sqrt(Int)]
 NC_RegenPerSpirit = 0.027875 * sqrt(Int)
 NC_RegenPerMP5 = 1

While casting:
 C_RegenPerInt = Coeff * NC_RegenPerInt
 C_RegenPerSpirit = Coeff * NC_RegenPerSpirit
 C_RegenPerMP5 = 1

As you can see, MP5 is the only stat whose effect remains constant both in and out of casting. If you have no talents allowing mana to regenerate from spirit while casting, MP5 is the only way to do so. Even with them, MP5 is still quite valuable, given the most common of these effects (listed above) cap at 30% spirit-based regeneration.

Multiple ratios do stack, but can never exceed 100%.


Research by Whitetooth[1] shows that since Patch 2.4, mana regeneration is uniform across all classes and based on the following formula:

Mana Regen = 5 * sqrt(Int) * Spirit * Base_Regen In effect, the regeneration rate depends on Int, Spirit and character level. A 1% increase in Spirit increases mana regeneration by 1%, and 1% Intellect yields 0.5% more regen. This is a rough rule of thumb, but is accurate enough for most situations.   Intellect doesn’t influence mana regen linearly, rather the square root of Intellect is used. This means that higher Int values yield diminishing returns, as can be seen in the following table:

Intellect vs Spirit Coefficient




Grants up to 10 party or raid members mana regeneration equal to 0.25% of their maximum mana per second

  • Vampiric Touch (Priest): Causes Shadow damage over time and enables the Replenishment effect to be triggered by Mind Blast.