Theorycrafting: Game Mechanisms explained


Theorycrafting posts used to be something really common on the old forums. Many people wanted to know how things worked, either by simple curiosity or to improve their play-style. However, once all those curious people got their answers, theorycraft became less interesting, and the rare posts I've seen were when an update brought some new things to calculate or to understand.

For newer players, or players that just started to wonder about something, the fact that there is almost no place to find theorycraft anymore (as no one posted that on the new forums) is a problem. Therefore, I am writing this little guide to complete the other guides. I am not posting this in the general forums because I am not good enough at tanking or physical damaging theory. I am a priest, and know about the priest class mostly. Therefore, I made this guide with priest tips here and there, while trying to keep a general point of vue.

As there are many questions that I have no answer to, I have put some few part in italic to show what I don't know. I would love to get answers (documented ones: either a real test with numbers or a link to a blue post). If you have some, post them and I'll update my posts.

Also, of course, if there is something that you didn't understand, feel free to ask. Also feel free to suggest a little guide on another subject if you've always wondered how something works.

I will start with only two little guides about two things that many, many, many people don't know well about: the difference between School of Magic and Spell Line, and how the resistances, spell hit and spell penetration work. A guide about mana regeneration (spirit, mp5, 5sec rule, etc...) and one about downranking are to be made (or maybe copy/pasted first until I have time to give them a good form).



Summary

• School of Magic VS Spell Line
  • Schools of Magic
    
  • Spell Lines
    
  • Consequences and common misunderstandings
    • Incoherences
      
    • Counterspell, Kick, Pummel, Shield Bash, Spell Lock
      
    • Shadowform and Holy Spells
      
    • Shadowform's cast, Shapeshifts
  
  
• Magical Resistances, Spell Penetration, Spell Hit
  • Two barriers
    • 1st barrier: Hit chance
      How many points in Shadow Focus?
    • 2nd barrier: Spell resistance / penetration
  • Holy resistance
    
  • Dispel, Mass Dispel, Purge, Cleanse, Silent Resolve
  
  
• Threat and Aggro
  • Threat list
    
  • Threat points
    
  • Aggro, and how (not) to pull it
    
  • Taunt
    
  • Fade and how to use it well
  
  
• Mana regeneration (Spirit, MP5, 5 seconds rule)
  To be made
  
  
• Downranking
  To be made

School of Magic VS Spell Line

• Summary
  • Schools of Magic
    
  • Spell Lines
    
  • Consequences and common misunderstandings
    • Incoherences
      
    • Counterspell, Kick, Pummel, Shield Bash, Spell Lock
      
    • Shadowform and Holy Spells
      
    • Blackout and Shadow Weaving procs
      
    • Shadowform's cast, Shapeshifts
  
  
  
• Schools of Magic
  There are six schools of magic in the game (or seven depending on if you consider Physical damage as a School of Magic or not):
  • Arcane
    
  • Fire
    
  • Frost
    
  • Holy
    
  • Nature[/u
    
  • [u]Shadow
    
  • Physical is sometimes considered as a School of Magic. It is coded as a School of Magic in the game. See the Consequences and common misunderstandings part.
  Each spell has a School of Magic. School of Magic is what (usually) matches the color of the animation of the cast (Exception of Holy Fire between its two updates: it used to be a Fire School spell and had the Fire School animation, it was changed to Holy School, but kept its animation during some time. Now it's a Holy School spell with a Holy School animation). Some instant spells don't show the School of Magic during their animation, for instance Psychic Scream or Mind Flay, because they have their own animation. The colors are:
  • Arcane: Light Blue
    
  • Fire: Orange
    
  • Frost: Darker Blue
    
  • Holy: White
    
  • Nature: Green
    
  • Shadow: Black
  The resistances apply to those Schools of Magic, and are not linked to the Spell Lines.
  
  
• Spell Lines
  Spell Lines are the three tab of the spellbook that every class has. Therefore, there are far more Spell Lines than Schools of Magic. The list is:
  • Druid: Balance, Feral Combat, Restoration
    
  • Hunter: Beast Mastery, Marksmanship, Survival
    
  • Mage: Arcane, Fire, Frost
    
  • Paladin: Holy, Protection, Retribution
    
  • Priest: Discipline, Holy, Shadow Magic
    
  • Shaman: Elemental, Enhancement, Restoration
    
  • Rogue: Assassination, Combat, Subtlety
    
  • Warlock: Affliction, Demonology, Destruction
    
  • Warrior: Arms, Fury, Protection
  Your three talent trees are your three Spell Lines too.
  
  
• Consequences and common misunderstandings
  
  
  • Incoherences
    Most of the time, when a Spell Line has the same name as a School of Magic, all the spells in this Line will be of the linked School of Magic. Therefore, Mind Blast is Shadow Magic (Spell Line) and Shadow (School of Magic). However, it is not always like that. There are many examples, mostly (maybe only) in the priest class. Discipline Line spells aren't always Holy School, but it can be even stranger:
    • Mana Burn: Discipline Line, Shadow School
      
    • Feedback: Discipline Line, Shadow School
      
    • Starshards: Discipline Line, Arcane School
      
    • Consume Magic: Discipline Line, Arcane School
      
    • Prayer of Shadow Protection: Shadow Magic Line, Holy School (!)
    
    
  • Counterspell, Kick, Pummel, Shield Bash, Spell Lock
    As specified in the tooltips of those abilities, they lock a School of Magic, not a Spell Line. Therefore, Shield (Discipline Line, Holy School) or even Prayer of Shadow Protection (Shadow Magic Line, Holy School) are locked with Flash Heal (Holy Line, Holy School). That makes classes that rely on only one School of Magic very weak against Counterspells, like Paladins that use only Holy School spells (even if they have a Retribution and a Protection Line).
    
    
  • Shadowform and Holy Spells
    Shadowform locks your Holy Line spells, but hopefully not your Holy School spells. That's why Shield and Dispel (and some others) are still useable in Shadowform even if they are from the Holy School.
    Shadowform used to lock all your "non-shadow" spells. I think it was the spells not in the Shadow Line, locking Mana Burn too for instance (Discipline Line, Shadow School), but I am not sure. The change is very old, I wasn't interested in the game mechanisms enough back then.
    
    
  • Blackout and Shadow Weaving procs
    Both those spells proc from Shadow Magic Line spells and not necessarily from Shadow School of Magic spells. Therefore, mana burn doesn't proc either, as it's a Discipline Line spell from the Shadow School of Magic.
    
    
  • Shadowform's cast, Shapeshifts
    Shadowform is a Shadow School spell (from the Shadow Magic Line). Therefore, it should be locked when you get your Shadow School counterspelled. However, you can still cast or remove Shadowform when your Shadow School is locked. It is because Shadowform is partially considered as a Shapeshift spell, as the Druids' Bear form for instance. Therefore, they are not really spells, you can cast them even when Silenced or Counterspelled. It is even "better" than the Paladins' Divine Shield or the Frost Mages' Ice Block, because even those two classes can cast their immunity spells while silenced, they cannot cast it when counterspelled: Counterspells create a cooldown on your spells of a School of Magic, and you can't cast a spell that is on cooldown, even Divine Shield or Ice Block. But Shadowform and other Shapeshift cannot be put on cooldown this way.
    
    The only exception that I am aware of is Gift of the Naaru, which, as mentioned by Escherichia, cannot be cast while in shadowform. This is a bit stupid, because it's a Racial Line (even if Holy School) spell. But hey! Stupid things happen when you let stupid people code! (I didn't say that, I swear, my keyboard wrote everything on its own).

Magical Resistances, Spell Penetration, Spell Hit

• Summary
  • Two barriers
    • 1st barrier: Hit chance
      How many points in Shadow Focus?
    • 2nd barrier: Spell resistance / penetration
  • Holy resistance
    
  • Dispel, Mass Dispel, Purge, Cleanse, Silent Resolve
  
  
  
• Two barriers
  When a caster casts an offensive spell on his target, this spell can sometimes be partially or totally resisted. How does this work?
  Basically, there are two barriers: A hit chance barrier, and a magical resistance barrier. There is no way to know which one, in Blizzard's code, is applied first, but it doesn't matter at all. Any order would give the same result. Therefore, I will consider that the 1st barrier is the hit chance one, and that the 2nd barrier is the resistance one.
  
  
  • 1st barrier: Hit chance
    This hit chance barrier applies to every spell. It can only create full resists.
    The caster's level is compared to the target's level. At equal levels, with no spell hit rating gear, the spell has a 96% chance to break this barrier. Hit rating will be converted into hit chance depending on the caster's level (at higher level, you need more hit rating to get the same hit chance in percents). It will be added to those 96%. The new value is capped at 99%, no caster has a 100% hit chance.
    The base 96% hit chance is for a fight at equal levels. It decreases when the target is of higher level than the caster (I am not sure if it increases when the target is lower level). If the target is a player, it decreases slowly. Though, in PvE environments, the decrease is pretty fast.
    Level difference:
    • 0 -> 96% base hit in PvE, 96% base hit in PvP
      
    • 1 -> 95% base hit in PvE, 95% base hit in PvP
      
    • 2 -> 94% base hit in PvE, 94% base hit in PvP
      
    • 3 -> 83% base hit in PvE, 87% base hit in PvP
      
    • 4 -> 72% base hit in PvE, 80% base hit in PvP
      
    • 5 -> 61% base hit in PvE, 73% base hit in PvP
    
    The only way to go through this barrier is to either level up if you haven't reached the level cap yet, or to wear spell hit rating gear and spec for spell hit talents.
    
    
    How many points in Shadow Focus?
    About Shadow Focus (Shadow talent to increase your hit chance with Shadow Spells by 2% per talent point, up to 5 points for 10% hit chance):
    • PvP
      It is obviously a waste to put more than 2 points in a pure PvP build. With 2 points, you reach 100% hit chance against a player of your level which is reduced to 99%. With more points in Shadow Focus, you will still be capped at 99%. If you have a spell hit rating on your PvP gear, you might even need less: If you have 1% hit from your gear, only put 1 point in Shadow Focus. If you have +3% hit, don't take Shadow Focus for PvP. More than +3% from your gear is also useless.
      
    • PvE
      If you are aiming for a shadow PvE build, you have to put several talent points in Shadow Focus. Unless your gear is exceptional, you won't reach the 99% cap on this first hit barrier against Worldbosses (which are considered level 73 in TBC) and level 73 bosses. To compare it with other Shadow talents, darkness increases your dps by 2% per talent point, while Shadow Focus increases your dps by slightly more than 2% per talent point (from 2.4% to 2%, ask me why if you don't understand why, it's just maths but I know some people aren't used to that), and it also increases your chance to land VE, to proc blackout and shadow weaving (even more than other spells, as they need the base spell to land, and then they also have to hit), etc... For sure a better talent than Darkness, and you'll have 5/5 darkness, won't you?
    
    
  • 2nd barrier: Spell resistance / penetration
    This second barrier applies a different way depending on the spell. There are two kind of offensive spells in World of Warcraft:
    • Binary Spells
      Binary spells are like Mind Flay, Vampiric Embrace etc... They cannot be partially resisted. There are only two possibilities (cf. binary): Either the spell gives its full effect, or it is totally resisted.
      
    • Non-binary Spells
      Mind blast is a non-binary spell. Sometimes, you will see in your combat log "Your Mind Blast hits Mob for 750 (250 resisted)." It means that the first barrier has been passed and the second barrier has had a partial effect.
      What I don't know: Are spells resisted before or after Shields' damage absorption and protection potions? I would say before, but I have no source about that
      Shadow Word: Pain has also been changed a bit, I believe that it's not really binary anymore. The cast is binary. Each tick can be partially resisted. Anyone knows exactly how it works? And is it the same for every DoT (VT / MF)?
    
    The caster's spell penetration is removed from the resistance of the target against the School of Magic (see the School of Magic VS Spell Line part) of the spell. This gives a value (at least 0). You add this value to the base resistance of the target due to level difference (I don't know the exact numbers: there should be a table that looks like the first barrier's one, but no one has written it or I haven't read it.). It seems that in PvE, the target gains 5 resistance per level above the caster (note that spell penetration won't help against this base resistance). It has been shown that there is such a base resistance in PvP (a priest had a partial resist on a smite against a player), but no number has been shown.
    These resistance values, as the "ratings" stats ("hit rating", "critical strike rating", etc...) are down-valued when you are higher level. Also, unless it has been changed, the best resistance you can have against a level x mob or player is 5*x. Against a level 73 mob (or a worldboss), you would be at the max if you have 365. According to wowwiki, if you go past this number, it will lower the effect of your resistance (370 would be the same as 360, 375 the same as 355, etc...), but I have not verified that and i haven't read it elsewhere.
    At level 70, you should need around 4.8 resistance to reduce the average effect of the spells by 1%, capped to 75% if you have 365 resistance. This is done differently if the spell is binary or not:
    • Binary Spells: If your resistance gives you a x% effect reduction on a spell, you just have x% chance for the second barrier to totally resist the spell.
      
    • Non-binary Spells: If your resistance gives you a x% effect reduction on a spell, there will be formulas that I do not know that will produce probabilities for the following events to happen:
      • The spell is resisted by the second barrier
        
      • 75% of the damage is resisted by the second barrier
        
      • 50% of the damage is resisted by the second barrier
        
      • 25% of the damage is resisted by the second barrier
        
      • The spell isn't resisted
      
      The average damage taken will be x%, so you will have x_100% chance to take full dmg, x_75% chance to take 75% of the damage, x_50% chance to take half dmg etc, with x = 1 * x_100 + 0.75 * x_75 + 0.5 * x_50 + 0.25 * x_25 and x_100 + x_75 + x_50 + x_25 + x_0 = 1. I have no idea about what formula gives those x_something. Some samples can be found on the official websites, but it isn't something you can extrapolate from.
  
  
  
• Holy resistance
  Spells from the Holy School of Magic (see the School of Magic VS Spell Line part again) has no resistance shown in the character frame. Actually, there is no real holy resistance. You do not get holy resistance through Mark of the Wild. You do not get holy resistance from arcane resistance (This was probably true in the older patches, but has been changed a long time ago from what I heard). The only holy resistance one has is the base resistance due to level difference. Therefore spell penetration will not help a holy caster at all (as the base resistance due to level difference cannot be lowered by spell penetration). It explains how rare it is to see a holy spell partially resisted by a player: you would have to cast a holy spell on a player that has a sensibly higher level, which doesn't happen that much :)
  
  
  
• Dispel, Mass Dispel, Purge, Cleanse, Silent Resolve
  Purge and offensive dispels are offensive spells, though they cannot be resisted. However, if the target has buffs that are protected by Silent resolve (20% chance that your spells aren't dispelled) or something equivalent, they can "not work", but it's not a resist message that is shown (it says "You failed to dispell xxxx").

Threat and Aggro

• Summary
  • Threat list
    
  • Threat points
    
  • Aggro, and how (not) to pull it
    
  • Taunt
    
  • Fade and how to use it well
  
  
  
• Threat list
  Whenever a mob is in combat, he creates a threat list that includes the players he will try to kill. You are added on a mob's threat list if:
  • You enter his aggro range while he isn't in combat (you can go close to most mobs that are already fighting without being added to their threat list)
    
  • You use an offensive ability on him
    
  • You use a defensive ability on a player that is in his threat list
    
  • If the mob has a random target attack, or some AoE ability, getting hit by one of those will also put you in his threat list.
    
  • Some mobs are linked to each other, then, getting on the threat list of one of them will put you in the other's list as well.
    
  • Most "big" bosses will put you in their threat list wherever you are in the instance. Example: your guild is wiping in AQ40, you died first and run back to the instance before the fight is over, you get in combat while entering, and the boss teleports you to him when he has no target close to him: you die again.
  
  You are removed from a mob's threat list only if:
  • Well, if the mob dies :p
    
  • If you die
    
  • When you get the mob out of his patrolling range (some kind of area that I don't really know details about) and don't direct damage him during at least 6 (is it 6?) seconds.
  
  When a mob is still alive and his threat list is empty, he runs back (faster than his normal speed) to his normal position, and you cannot do anything to him until he's back (he will "evade" your attacks). This explains why hunters are good at kiting: they have a lot of direct damage that they can easily do while running away. Priests have few direct damage spells and only SWD is instant.
  
  
• Threat points
  Once you are on a mob's threat list, many things that you do will create threat points. If you have too many threat points (too much threat), you will take aggro (see the Aggro part). What creates threat points:
  • Dealing damage to the mob creates 1 threat point per damage
    
  • Dealing damage to another mob will not create any threat point. At worse, it'll add you to the threat list if you aren't in yet.
    
  • Healing someone on the mob's threat list creates 0.5 threat point per actual healing (if someone has 4000/5000 hp and you heal him for 3500, only 1000 healing will create threat (500 points) and the rest will not be counted).
    
  • Healing someone not on the mob's threat list, even if he's fighting near you, whatever the other mobs' threat lists are, will not create any threat point.
    
  • Regening mana is the same as healing (0.5 point per mana).
    
  • Buffing people on the threat list will create some threat, the amount depends on the buff.
    
  • Debuffing the mob will create some threat, once again it depends on the debuff.
  
  In most big fights (linked mobs in an instance), the threat points are usually something like that (except in fights against mobs that have special crowd control or threat control abilities):
  • The healers have the same threat points on every mob's threat list.
    
  • Each tank has a lot of threat points on some few (usually 1, sometimes 2, rarely more) mobs' threat list and 0 on the others'.
    
  • The DPSers have threat points on the target they are killing
  
  That explains why, when a tank dies, if he was tanking the target getting killed, the mob will go hit a DPSer, but if he was tanking a target "in the background", the mob will usually go for a healer.
  
  
• Aggro, and how (not) to pull it
  Unlike what many people think, you don't pull aggro simply because you have more threat points than your tank. To pull aggro (except special abilities like taunt), you need:
  • To have 10% more threat points than the player the mob is hitting and to be in melee range from the mob
    
  • Or to have 30% more threat points than the player the mob is hitting (being out of melee range).
    
  • Or if the mob's current target dies or gets a feign death / cyclone / blessing of protection / ice block / banish / divine shield. It is basically the same thing, as it means that the old target will now have 0 points and that you will, therefore, have far more threat than him :) But it is to point out the fact that after this kind of thing, it is the player the highest on the threat list that takes aggro.
  
  Though, don't think that you can just stay out of melee range casting your spells and staying at 25% more threat than your tank with no risk. There is a major risk doing that (except the risk to go over 130% by mistake, "thanks" to a nice crit). Picture this situation:
  Your tank has around 10,000 threat points. You have around 12,500 threat points:
  • If the mob comes near you for some reason, you will pull aggro. See "taunt" later, but if the mob is immune to taunt, the tank will have to generate 2,500 threat points to equal your threat, and the around 1,300 more to be 10% above you and get aggro back.
    
  • The tank dies and the backup tank had only 12,000 threat points: same as above, the backup tank won't be able to take aggro back easily.
    
  • A mage or a hunter pulls aggro and uses ice block or feign death: you have more threat than the tank and therefore you pull aggro when the mob is looking for a new and not immune target (it's of course the same with BoP).
  
  
• Taunt
  Taunts are abilities that make a mob attack you during some few seconds. It has several effects: It generates the threat points required for the taunter to catch the player that currently has aggro (if a mage overaggroes by getting 13,000 points while the tank has 10,000, taunt will create 3,000 points so that the tank now has 13,000 too). Also, it forces the target to attack the taunter during 3 seconds, even if someone should have pulled aggro during this time. Note that the warrior won't need to have 10% more than the mage: Taunt gives aggro, gives threat, and makes the target attack you 3 second.
  Usually, when your tank uses a taunt, it means that he doesn't have enough threat points to pull aggro fast another way (Thanks to Iya for showing me a big mistake here and to Lavina for giving a source that confirmed this mistake).
  The really nice part about taunt is that, as explained in the paragraph above, a mob will usually not change target unless someone has a lot more threat than the player currently tanking. So it has a huge use in this kind of situations:
  The tank has 10,000 points. You overaggro by getting 13,500 points. The tank taunts, therefore the mob comes back to the tank. During taunt, you stop doing anything and the tank deals some threat points. After taunt, the situation will be something like: Tank (11,500 points), You (14,000 points cause you didn't stop fast enough). And the mob won't come back to you because you don't have 30% more than the tank.
  Another example: The tank still has 10,000 points. You have 12,500. A mage overaggros and uses ice block. You take aggro, the tank taunts, gets aggro back. The threat points of you and your tank are the same as they were before the ice block + taunt, you are still 25% above him, you don't even have to stop DPSing.
  
  
• Fade and how to use it well
  Fade is a strange ability. It reduces your threat points (not the rate at which you generate them) during some time, and when it's off, you get your threat points back. It's the contrary of a taunt: it does not remove threat, it only acts on aggro. Thus you will tell me that fade is useful only when you pull aggro, and it is almost true.
  Fade is useful when you pull aggro early in a fight. It's not as taunt, the mob will not stop hitting you if you had too much threat. I don't know the exact threat reduction that fade involves, but let's say it removes 2,000 points. If you use it early in a fight while pulling aggro: Your tank had 5,000 points, you pulled with 6,500, fade gets you back to 4,500 and the tank has ~11% more than you and pulls aggro back. At the end of the fade, you get your 2,000 points back, but the tank has generated threat while you have been less active, and you won't have 30% more than him (don't stay near the mob cause then, 10% would be enough: if you pull aggro and fade works, run out of melee range fast).
  Later in a fight, the same situation would be: The tank has 10,000 points, you pull aggro with 13,000, fade brings you back to 11,000 and nothing happens (or yes, something happens: you die).
  Now, the secret use of fade. Believe me, it's the only use it has late in a fight, but it's still worth it and will save your group now and then. Let's take the situation with 10,000 points for the tank and 12,000 for you. A mage pulls aggro. You press fade fast and gets away from the mage, away from the tank, away from everything. Your threat is now 10,000, the tank has a bit more than 10,000 as he hasn't stopped playing. The mage now uses ice block. You should have pulled aggro with your 12,000 points, but now, the tank has more than you. He pulls aggro back, fade fades (sorry :p), and you have less than 30% more points than the tank.
  
  Woow, I am not sure if it was easy to understand. Fade is a complicated mechanism, even more than taunt.

I'll also link a threat guide from the tanks' point of vue for those who want to learn more about it:
http://forums.wow-europe.com/thread.html?topicId=94319875

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There are potions which help you resist some part of holy damage.

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Q u o t e:
There are potions which help you resist some part of holy damage.

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No, they absorb holy damage, they don't increase your resistance to holy spells :) But I'll add that.

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Q u o t e:
No, they absorb holy damage, they don't increase your resistance to holy spells :) But I'll add that.

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Right, failed to express myself correctly.

I reported this thread FOR SPAM!

No.. Actually it was a sticky. :)

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Q u o t e:
I reported this thread FOR SPAM!

No.. Actually it was a sticky. :)

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Thank you :)

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Q u o t e:
Right, failed to express myself correctly.

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No problem, when the forum lets me edit my old posts I'll add that: it was something actually missing and I'm happy you pointed it out.

SWP is not a binary, the ticks can resist. It rolls against resistance every tick, but most likely not with full modifiers, that would make the damage ridiculously low without *massive* +hit.

Reported for sticky and linked from my FAQ :)

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Q u o t e:
SWP is not a binary, the ticks can resist. It rolls against resistance every tick, but most likely not with full modifiers, that would make the damage ridiculously low without *massive* +hit.

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The thing is that the cast (application of the debuff or not) is binary. After that, I hope that there is only a resistance barrier (else it sucks :p) but I'm not sure, I'm not sure either if, as you say, it's a total barrier or only a part of it. Maybe even than the application of the debuff only has to go through the hit barrier, and then the ticks through the resistance one.
Anyway, it requires further testing. I'll edit my post to make this appear. Thank you for your feedback :)

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Q u o t e:
SWP is not a binary, the ticks can resist. It rolls against resistance every tick, but most likely not with full modifiers, that would make the damage ridiculously low without *massive* +hit.

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But it is binary..., if you hit the tick, you hit all its damage, that is.

Edit:
Good post Layrajha, btw, congratulations. I'm waiting for the remaining parts to be completed tho but for now it is 10/10.

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Q u o t e:
Good post Layrajha, btw, congratulations. I'm waiting for the remaining parts to be completed tho but for now it is 10/10.

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Thanks :) Happy to please you.

Agreed, thanks a lot for this fantastic post, something which has been missing from these forums for a long time. Looking forward to the rest of the posts.