Archive for 7. General Game Mechanics

Game Mechanics


Threat mechanics

Healing agro has a multiplier of -50%. This means that every time you heal someone for 1000, you generate 500 threat. This goes for ALL healing classes except the paladin, which has a healing threat modifier of -75% meaning his healing generates half the threat of druid/priest/shaman healing.

Healing agro on multiple mobs:
Healing agro works with the threat spreading concept. This means that the threat generated is divided between the mobs the threat effects.

Giving a few examples on the statement above.
Example 1: You are involved in combat with a single mob. You heal the main tank for 1200. The result is that you generate 600 threat on the mob.
Example 2: You are involved in combat with 3 mobs. You heal the main tank for 1200. The result is that you generate 600 / 3 = 200 threat on each mob, or said in another way, the healing threat is divided between the amount of mobs being tanked.

It should be noted that healing agro is not generated on crowd controlled mobs. A healer won’t be generating agro on a sheeped, rooted, seduced mob etc. and that mob doesn’t count as in combat in regards to healing agro in the two examples above. In regards to roots, roots only count as crowd control if the rooted mob is not able to attack a party member with melee attacks, ranged attacks, spells. If a mob is rooted but still able to attack something, healing threat is still generated.
Power gains (gains of mana from potions, gains of rage from Furor etc.) act in the same way in that the threat is split between multiple mobs. In the “Bear Threat” section, it was shown how shifting into bear generates 50 threat (10 rage for 5 threat per rage point), but if two uncontrolled mobs are present, the threat is divided for 25 threat each.
Heal from Improved Leader of the Pack generates no threat.
Healing agro with Subletly or other threat reduction buffs:
Threat reduction buffs stack multiplicatively. Say you heal for 1000 and you are specced 5/5 Subletly (20% threat reduction talent), you will generate 1000 * (0.5 * 0.8) = 400 threat. Same goes with a paladins Blessing of Salvation or a shamans Grace of Air totem.

Healing agro and crits:
A heal being a crit has NOTHING to do with the threat generated apart from the amount being healed. If your healing spell crits for 2000 it will still only generate 1000 threat.

Overhealing causes no threat. If a person is lacking 1000 HP and you heal him for 2000, you will still only generate threat for the 1000 healing actually needed (= 500 threat). Healing a person on full HP generates no threat, though it will put you in combat if the person healed is already in combat.

How “Healing over Time” spells generate threat:
The threat from HoTs are applied every time the HoT ticks. This means that there is no initial threat from applying a HoT (though it will put you in combat with a mob if the target of your HoT is in combat with that mob).

The above have led to confusion, because many druids believe that casting HoTs on a tank just before he pulls a boss will generate threat and possibly wipe the raid. This is partially true. In order for a healer to generate threat with HoTs, that healer has to be in combat with the mob. Against a raid boss that automatically puts everyone in combat when engaged, it can be dangerous to HoT the tank before pulling unless you have competent hunters Missdirecting, but on 5 man bosses or on normal pulls that doesn’t put you in combat, hotting the tank before the pull is perfectly safe.

Scaling Mechanics

Various abilities and items in WoW scales with stats and talents. Offensive melee abilities scale with Attack Power, offensive spells scale with +damage and healing spells scale with +healing, some items scale with talents as well.

Healing Abilities

Various healing abilities in WoW take the spellpower into account and improve the power of your heals.

Note that the mechanic for spellpower changes if you choose to downrank spells (say cast a low rank rejuvenation instead of your max rank, that rank is penalized and therefore receives less effect from +healing gear).
Note that before spellpower was introduced, the old stat that increased healing was known as +healing. As a result, the numbers below are only approximations, meaning that when we write that Rejuvenation takes 160% of your spellpower into account, we actually mean approximately 160%. Numbers might be slightly off.


  • 160% of your spellpower is added to the spell, spread over each of the 4 ticks (40% per tick). Additional ticks from talents (Nature’s Splendor), glyphs, setbonuses or similar won’t decrease what each tick heals for, it always heals for the same (the spell just lasts longer).


  • Approximately 66.7% of your spellpower is added the the HoT over all 7 ticks (9.52% per tick);
  • Approximately 64.6% of your spellpower is added the end heal;
  • The spellpower bonus of Lifebloom is, as of patch 2.1, added to all 3 stacks of Lifebloom, so stacking lifebloom 3 times will tripple the 66.7% of your spellpowers contribution.
  • The end heal of lifebloom is unaffected by the amount of stacks of Lifebloom. It will always heal for the same regardless of the amount of stacks.
  • The end bomb of lifebloom doesn’t count as your own healing. Therefore, all agro generated by the end bomb of lifebloom is attributed to the person healed, not to yourself.


  • Takes approximately 58% of your +healing into account on the initial heal;
  • Takes 142% of your +healing into account on the HoT spread over 7 ticks. More ticks by talents like Nature’s Splendor or similar increases doesn’t affect what each individual tick heals for.

Healing Touch:

  • Takes 171% of your spellpower into account.


  • Takes 152% of your spellpower into account (38% per tick).


  • Always heals for exactly the same as 4 ticks of Rejuvenation or 6 ticks of Regrowth, even when Swiftmending other druids HoTs disregarding their gear (but not their talents, an untalened Rejuvenation from a Feral Druid will be Swiftmended for less because it takes the Feral druids lack of restoration talents into account. It will, however, still use your gear and spellpower). See the Regrowth or Rejuvenation section for calculating their respective ticks.


Healing Talents

Here is a few of the different talents

Gift of Nature:

  • Always applies to the end heal of the talent, effectively increasing it by 10% including taking +healing gear into account;
  • Stacks additively with Improved Rejuvenation (10% + 15% = 25% on Rejuvenation).

Improved Rejuvenation:

  • Always applies to the end heal of the talent, effectively increasing it by 15% including taking +healing gear into account.
  • Stacks additively with Gift of Nature (10% + 15% = 25% on Rejuvenation).
  • Also increases the amount healed by Swiftmend when Swiftmending a Rejuvenation.

Empowered Touch + Empowered Rejuvenation:

  • Increases the gain from spellpower by the percentage specified, meaning that it acts like you had X% additional spellpower.
  • While Empowered Rejuvenation states “your healing over time spells”, it also affects the non-heal over time part of those spells. This means that it also works with the initial Regrowth cast, as well as it works with the end bloom of Lifebloom


Threat Auras
Effect Threat Multiplier
Baseline modifiers (all characters)
Damage caused 1.0
Healing caused 0.5 * healing done (overheal not counted)
Threat Modifying Abilities
Ability Threat Bonus/Reduction
Power Gain (Mana) Base threat is 0.5x Mana gained (only certain effects)
Power Gain (Rage) Base threat is 5x Rage gained (only certain effects)



Casting speed calculation

% Spell Haste at level 80 = (Haste Rating / 32.79)

New Casting Time = (Base Casting Time)/(1 + (% Spell Haste / 100)


Note that “base casting time” is after talents. For example, a warlock’s shadow bolt is 3.0 “base cast time” under normal usage of the term “base cast time”. However, for the purpose of this formula, you should use the improved cast time from your talents (2.5 cast time, in this example) if you have that talent, or the formula will not give the correct result.

Essentially, 1% haste allows a player to cast 1 additional spell in the time it would normally take to cast 100 spells. If the spell is a 3 second cast, that means one can theoretically cast 101 spells in 300 seconds, or 2.97 seconds per spell.

To determine the amount of time taken to cast a given sequence of spells, the reverse formula can be used, where Base Casting Time is the sum of all the spells in the given sequence:

Haste Rating needed at level 80 = ((Base Cast Time / Desired Cast Time) – 1) * 32.79 * 100

Example: I am a level 70 mage, and I want my Fireball (3s), Fireball (3s), Scorch (1.5s) cast chain to take 6.5 seconds. Therefore, a [1577 * ((7.5 / 6.5) – 1) = ~243 Haste Rating] is required.

Improving casting speed

Various sources that improve casting speed are listed on the Casting Speed improving items page.

Note: Haste rating stacks additively with itself but haste stacks multiplicatively. That means that if you have 158 haste rating, you will have +10% haste, no matter how many sources and items that haste rating comes from. If you then use troll Berserking for +30% haste, you would have 110% * 130% = 143% haste.

Losing casting speed

Chance of Ignoring Spell Interruption When Damaged = 100% – Chance to Be Interrupted By Damage

The chance to have your spells delayed by damage is additive. If you have a talent for 70% chance to avoid spell interrupts, and a paladin with concentration aura (another 35%) is in your party, you will not receive any spell interrupts from damage.

NOTE: The Spell Pushback mechanics have been changed as of release 3.0. Now, only the first two damaging attacks received will cause spell pushback, and subsequent damage will not. The talents that used to reduce the odds of spell pushback occuring now instead reduce the amount of casting time lost when pushback occurs.

Global Cooldown

Haste Formula

The global cooldown for casters with no haste is 1.5 seconds. Haste reduces the global cooldown according to the general formula for haste:

NewCastTime = BaseCastTime * ( 1 + HasteRating / ( RatingConversion * 100 ) ) ^ 1

RatingConversion represents the haste rating required for 1% haste at a given level.

Haste Rating Required Per 1%
Level 60 Level 70 Level 80
10 15.77 32.79


Percentage Reduction

The amount of haste required to reduce the global cooldown to a desired value can be calculated by:

Haste = ( ( BaseCastTime / DesiredCastTime ) – 1) * 100
For example: 100% haste = ( ( 1.5s / .75s ) – 1) * 100

Haste Rating

Rearranging the general formula for haste:

HasteRating = ( RatingConversion * 100 ) * ( ( BaseCastTime / NewCastTime ) – 1 )

For example: 500 hasteRating = ( 10 hasteRating * 100 ) * ( ( 1.5s / 1s ) – 1 )

To reduce the global cooldown to an arbitrary value of 1 second, it would take 50% haste or a haste rating of:

Level 60 Level 70 Level 80
500 788.5 1639.5




How Latency Affects Maximum Healing Potential

Latency plays a huge role in determining how effectively you can heal and what your maximum healing potential is. Consider this, if you are spamming heals with a 1.5 sec cast time, then you could potentially make 40 heals per minute. However, add in 100 ms of latency, and suddenly your cast time becomes 1.6 sec. In this case, you can only cast 37 times a minute.

Now this may not seem like a huge difference but look at it this way. With 300 ms (therefore a 1.8 average cast time), you could cast 33 times in 1 minute, which means that you could have suffered a 17.5% loss in your maximum healing potential. The subtleties of latency are intricate and so perhaps I am overstating the facts a bit, but any way you run the numbers you are still gimped in your healing ability depending on your latency.

Take another example. If 300 ms translates into 0.3 sec of extra cast time, then there would be no way I could keep LB stacks on 4 targets at once.
1.5 x 4 = 6.0 sec
1.6 x 4 = 6.4 sec
1.7 x 4 = 6.8 sec
1.8 x 4 = 7.2 sec

Each cycle now exceeds 7 sec (the time of LB) and therefore keeping 4 stacks on 4 targets would now prove impossible. That being said, it’s probably possible to make a 4-target cycle work with latency over 300 ms just because of the intricacies of latency (which I don’t understand thoroughly enough to give comment or direction). But for our purposes, we’re going to assume that 300 ms of latency translates into 0.3 extra seconds of cast time.

How This Information Affects Trinket Selection
The main thing I want to use this information for, is to discuss the way certain trinkets proc if they have a standard chance per cast to proc. For example, if a trinket has a proc rate of 2% per cast, then we assume that it will proc once every 50 casts. With absolutely no latency, this translates into 1 proc every 75 seconds (50 x 1.5 = 75). However, with 300 ms of latency, this changes the proc rate significantly to (potentially) 1 proc every 90 seconds (50 x 1.8 = 90). This can significantly change the value of that particular trinket, so when choosing which trinkets are right for you, please be conscious of your average latency, and how it will affect that trinket’s performance

Global cooldown


To check your current Global Cooldown use the Following Macro:
A global or universal cooldown, frequently shortened to “GCD”, is the cooldown which starts every time you start to cast a spell, and it affects all of your class spells. There are exceptions to this, however, as noted below. The basic rule of thumb is that if the spell affects the casting of the next spell, it will not activate the global cooldown.
If the spell has a casting time less than the global cooldown (or instant cast), you generally have to wait the remainder of the global cooldown. If a spell with casting time is interrupted before it has finished casting, the global cooldown will be canceled, meaning you can start casting a new one immediately.
The global cooldown is generally 1.5 seconds for all classes except rogues and cat form druids, whose abilities are mostly one second global cooldown. Shaman totems also only trigger a one second global cooldown. The global cooldown affects the wait for the next ability, so using an item or ability with the standard 1.5 second cooldown will require waiting that long before a 1 second global cooldown ability can be used.




/cast Lifebloom
/script local start, duration, enable = GetActionCooldown(4);DEFAULT_CHAT_FRAME:AddMessage(duration);



 Spell Queuing, GCD testing (on 3.09)

TLDR: It looks to me as if spell queue-ing will take cast attempts up to about 0.3s early. This will work in the GCD, but will not work during the first 1.0s of the GCD.

I did some timing tests on a dummy in Stormwind, to start to get some quantitative values for 1s Wrath. Times are rounded to tenths of seconds.

First SF. My tooltip read 2.74 seconds. Nature’s Grace cast time is about 2.3s. The columns show different times, such as 2.7 for 2.7s, the expected cast time.

The rows are:

Cast: Time from one start-cast to the next.

Dam: Time from when start-cast to damage reported. I include this row just because it should be independent of any skill on my part. Any variance is due to Blizz, my computer, or my network.

Fail: Time stamps (relative to the previous start-cast) at which I got “Another action is in progress” message.

The last three rows are the same, except with Nature’s Grace.

The internal cells show counts. For instance, there were eight sF casts which began 2.8s after the previous SF cast.

SF	Expected: 2.7, 2.3 NG
Time	1.1	1.2	1.3	1.4	1.5	1.6	1.7	1.8	1.9	2.0	2.1	2.2	2.3	2.4	2.5	2.6	2.7	2.8	2.9	3.0	3.1	3.2	3.3	3.4	3.5	3.6	3.7	3.8
Cast														1	2	4	7	8	4	2	1		1			1
Dam																1	1	1	8	4	5	3	3	2				1
Fail	1				2	1		1	2	2	2	3	2					1
NG Cast											1	2	3	1
NG Dam												1		1	1	1	2
NG Fail						1	2		1	1

My intended casting style is to triple-tap my SF button (middle finger), beginning a bit before my cast bar reaches the red on Ice HUD.


22/31 non-crit casts started pretty much on time (at most 0.1s late). Obviously it is possible to chain-cast SF. All of the NG casts started on time.

Damage tends to be reported, on average, 0.1s or 0.2s after spells are completed. There may actually be a vertical travel-time on SF. Also, the damage times were very inconsistent.

The “Another action is in progress” message can occur anywhere from about 1s after the previous cast begins to about 0.3s before the previous cast finishes.

For IS I did about the same thing. However I spent part of the time spamming the button rather than doing the triple-tap. The “fail” messages I got for IS (and for Wrath) were “Not yet ready.” Tooltip time for Wrath was 1.37s, which should also be my GCD.

IS	1.4
Time	0.0	0.1	0.2	0.3	0.4	0.5	0.6	0.7	0.8	0.9	1	1.1	1.2	1.3	1.4	1.5	1.6	1.7	1.8
Cast													2	5	20	8	8	5	1
NR	1	8	7	5	10	3	5	3	5	1	1

35/49 casts started on time (or at most 0.1s late). Not-Ready messages occured from 0.0s to 1.0s. Apparently key-presses after 1.0s were successfully queued.

For Wrath, I went back to the triple-tap tactic. I got “Not ready” messages during Nature’s Grace. No “Fail” messages otherwise.

Wrath	1.4	1
Time	0.8	0.9	1	1.1	1.2	1.3	1.4	1.5	1.6	1.7	1.8
Cast					2	1	8	7	5	1
NG Cast			1	1		2	1	2			1
NG NR	1	1	1	1

Non-crit Wrath seemed to do well. 18/24 were “on time.”
NG Wrath results are ugly. Out of eight casts, only 2 were “on time.” I also managed to get two “late” Not-Ready messages (at 1.0s and 1.1s). The WrathCalcs 1.4s cast time for NG Wrath is just about right for me on these results.

Note: My Wrath cast uses my pinky finger (I use an n52, Wrath is at the position that would be ‘A’ on a QWERTY keyboard, with pointer finger at ‘F’). I suppose it is possible that “keyboard ergonomics” make me do worse on Wrath. The fact that non-NG Wrath did ok, leads me to believe that is not really an issue. My main raid spell bindings (by position): ‘A’=Wr, ‘S’=SF, ‘D’=MF, ‘F’=IS.

Other Theorycraft topics:
Nuke Base Damage

I did a respec and checked. At 80, untalented Wrath does (tooltip) 557-627, 4 more than when it was learned at 79. Untalented SF does 1038-1222, 10 more than when it was learned at 78. Note: I say untalented. I was 5/0/13 when I remembered to look. I did not have Moonfury at this point.

Omen of Clarity

In the tests above there were 3 OoC from SF, 3 from IS, and 1 from Wrath. I continue to see numbers that are a better fit for 6% (likely 3.5/60 = 5.83%) rather than 3.5 PPM.

 by Erdluf



World of Warcraft terminology

HoT – Heal over time. The phrase HoTs is used as a gathering umbrella for spells that include a Healing over Time component, after you have finished casting. Examples: Lifebloom, Rejuvenation, Regrowth.
FSR – Five Second Rule. Every time you finish casting a spell (except NS), you now have 5 seconds until your Spirit will regen as it does normally. Being “within the FSR” means that you have casted a spell, and now do not have full Spirit regen.
HPS – Heal per second. Means how much a healing spell heals per second. For example, your rejuvenation ticks for 999 every 3 seconds. The spell has a HPS of 333. If the spell is not a HoT spell, HPS is identical to HPSC.
HPSC – Heal per second casting. Means how much a healing spell heals in total, per second you spend casting. For example, a spell heals for 3000 and you spend 3 seconds casting. The spell has a HPSC of 1000.
HPM – Heal per mana. Means how much each mana point you spend on a spell, heals the target. For example, a spell costs 100 mana and heals for 1500. The spell has a HPM of 15.
HPT – Heal per tick. For example, your rejuvenation heals a target for 1200 over 4 ticks and 12 seconds. The HPT is 300.
GCD – Global Cooldown. Instant cast spells cause a 1.5 sec cooldown on all spells. This cannot be improved by spell haste rating, but can be improved by shaman Blood Lust.
Overhealing – How much of your healing done with one or several spells that “overheal”, ie lands on the target but does not do any good because it is already at full health. For example, a spell that heals a target for 3000. The target only needs 1000 healing done to be at full health. The Overhealing is 2000, or 66%.
Effective Healing – Raw healing minus Overhealing. In essence, how much you actually healed your targets.
Downranking – Generally refers to using lower ranks of a spell to get a higher HPM at the cost of a lower HPSC.
Resto druid – A druid healing using mainly the restoration tree, and most of the time Tree of Life (see The Talents).
Dreamstate druid – A druid healing using a mix of the restoration and balance tree (see The Talents).

NS – Nature’s Swiftness. A 21point talent in the restoration that all full-time healing druids will have. It makes your next nature spell instant cast (All healing spells are nature).
NG – Nature’s Grace. A talent in the balance tree that, on a critical spell strike, reduces the cast time of your next spell with 0.5 seconds.
ToL – Tree of Life, a 41 point Shapeshift form in the restoration tree that disables Healing Touch and Abolish Poison and Remove Curse, decreases HoT mana costs by 20%, and gives an aura to your Party which increases healing on party members by up to 25% of your spirit. See Tips&Tricks for an exploit.

Druid Facts


  1. Lacerate applies the innate threat and debuff even when the attack is blocked. A blocked Lacerate can also proc Primal Fury.
  2. Omen of Clarity has a procrate of 3.5 procs Per Minute when only using auto-attacks. Yellow attacks can’t proc OOC.
  3. Omen of Clarity does not get 3 chances to proc on Swipe.
  4. Feral Faerie Fire, Growl, AOE Taunt and Demoralizing Roar are considered spells, and can’t be cast while silenced.
  5. Cyclone has diminishing returns in PvE as well as PvP
  6. Cyclone diminishing returns 50%, 25% (6 seconds, 3 seconds, 1.5 seconds), NOT 6 seconds, 4 seconds and 2 seconds as some people believe
  7. Roots don’t break on their own damage. Forget what you heard in this regard of people telling you otherwise. Roots break early because the target receive external damage or because it (like other CCs including Polymorph and Sap) have heartbeat checks where they have a chance to break early. Nature Resistance on a target also increases the chance it will break early.
  8. When your target gains more nature resistance, he also increases the chance of roots breaking early.
  9. The more spellhit you have, the smaller the chance of roots breaking early is. Spell penetration has no effect in this regard unless your opponent already has nature resistance.
  10. Paladins and mages can’t bubble or Ice Block out of a Cyclone.
  11. Un-shifting is actually not a spell casting operation not even an action. You can do it while doing something else like running, gathering herbs, speaking to NPC’s, or even under the effect of sleep or other crowd controls like stun and fear (especially useful to cast Barkskin during a stunlock).
  12. Any shifting can be cast while being polymorphed. While you expect to be unable to act at all, druid morphing breaks other polymorph effects (it’s in the tooltip, but a lot of people don’t realize it). It’s extremely useful in PvP (mage’s sheep) but also in PvE, for example vs Hex cast by witch doctors or Jindo in ZG, sheep cast by spellbinders in BWL, or mage elite guard in black morass.
  13. Barkskin can be cast while being stunned or otherwise while under the effect of most Crowd Controls. Rogue and Paladin stuns as well as Fear comes to mind, yet it also works on Hunter freeze traps, and other mez effects. Barkskin is not useable while shapeshifted except for Moonkin and Tree of Life form.
  14. Barkskin only prevent interruption due to damage, not counter or silence abilities like Counterspell or Earth Shock.
  15. Faerie Fire, Cyclone and Thorns are Nature spells, they are susceptible to Nature resistance and immunity. Also see point 10.
  16. A 6th (and above) Lacerate does refresh the bleed stacks, and does apply the innate threat. Also, the Lacerate damage ticks aren’t reset when the ability is refreshed and will still stick on its usual 3 second timer.
  17. Feral Charge does not silence, it only interrupts the spell being cast and all spells in that School of magic (nature, frost, arcane, holy, fire, shadow).
  18. If Gift of The Wild (applies to group) is cast on a group made of various levels, it won’t be applied to targets too low level. The automatic rank downgrade only applies to the target your mouse cursor hits, might require a lower rank reagent, and that rank will then be applied without other downgrade to other members of your group (they won’t receive it if they are too low level). The level cap is 10 levels below the spell level.
  19. A Bear under Mind Control can’t be polymorphed (strategy used on some bosses in PvE to prevent a controlled player to damage the group). Use Fear or Hibernate.
  20. Despite the fact that it costs mana, the act of Shifting is not considered a spell, can’t be interrupted, and is not affected by silence.
  21. Swiftmend can only consume Rejuvenation and Regrowth. It can’t consume Lifebloom (The tooltip works exactly as it says). Swiftmend will always consume the Rejuvenation or regrowth with the least remaining duration, even if its other druids that casted those spells.
  22. Tree form is considered an Elemental. Warlocks can Banish you. You can’t be sapped or seduced.
  23. Moonkin form is still considered a Humanoid. While you can’t be polymorphed, because you are shapeshifted, you can still be Sapped or Mind Controlled.
  24. Travel, Flight, Aquatic, Cat and Bear forms are considered Beasts. Hunters can fear you, Druids can sleep you. You are immune to Priest Mind Control and Polymorph, but you still can be Mind Controlled by mobs because most of their abilities are not limited to Humanoids. Flight Form is immune to all crowd controls in midair, though you can still be crowd controlled while flying on ground level.