I'm still working on my Spell Penetration stats, but the amount of information needed to confirm or deny anything about it takes so much more information than all the other abilities due to so much luck factor in it. It's still more than a month off from even being ready to show publicly, but it's looking good so far...just so much information to gather and compute.

Key part right there. Warlock curses trivialize any sort of resistance, and the mobs that do have resistance are few enough that it is not worth giving anything else up to get spell penetration.

I have another question also related to resistances. I am unable to find any information about holy spell resistances by searching these forums, so I'm wondering if there's conclusive evidence about how offensive holy spells work? First, regarding level-based spell misses, do holy spells work like the other schools in this regard? (4% miss against same level, 17% miss against +3 level, etc.) I assumed that this is the case, but I've seen some people stating that offensive holy spells have a flat 5% miss rate against mobs of all levels. This doesn't make much sense to me, but after searching around I wasn't able to find information either way. Second, regarding partial resistances, do non-binary holy spells suffer the same 5% chance of partial resistance against boss-level mobs like the other schools?

It's not that mobs don't have resistances in PvE - a lot of trash and a few bosses do. Supremus has some amount of Fire Resistance, for another example of where spell penetration could be useful.

The situation is that there's an observed resistance on all mobs that are higher level than the caster that acts like resistance, but can't be overcome with spell penetration. CoS and CoE make it such that if a mob actually has resistances that aren't overcome by those spells, they'll probably be noticed through casual observation (88 resistance gives the mob a 19% resist rate) when the curses aren't up.

Any Paladin tank can tell you that the resist rate scales with level.

Yes.

Not quite, if these Haunts are the green ghosts that lead up to Curator trash -- as they cast a buff on themselves that increases all resistances by 200, which is purgeable/dispellable/stealable.

The only place where I've been unable to get around a high resistance score by any means other than spell penetration that sparks to mind right now would be Vazruden in Ramparts.

Has there been conclusive tests done to show that spell casts use either a two-roll or a single-roll system for determining hits and crits?

How exactly do you mean? As fire, I've had spells crit and be partially resisted by mobs. However, if a spell doesn't hit at all (full resist) there's no way to know if it would have crit or not. How would you test that?

In a single roll system hits, resists, and crits are all mutually exclusive results. In this system your spell crit rate is absolute. If you have a 30% crit chance and a 70% hit chance against a high level target, then 30% of your spells will crit, 40% of your spells will hit, 30% of your spells will be completely resisted. This is for a non-binary spell and disregarding partial resists, because we know partial resist is rolled for separately.

In a two roll system, hit is rolled for first, crits are rolled next after a hit is determined. So for the same 30% crit chance and 70% hit chance, only .3*.7 = 21% of your spells will crit, 49% of your spells will hit, and 30% of your spells will be completely resisted. Once again this is disregarding partial resists.

Given a sufficiently high crit chance and a sufficiently low hit chance, I think it would be easy to find out which roll system is being used, since the two systems generate two very different ranges for the expected values of crit chance.

Wowwiki says it's a two roll system (Spell hit - WoWWiki, the Warcraft wiki) and cites this man's forum post: WoW Forums -> Second round of One/Two roll research

Seems to be heavily criticized but if someone wants to take that scheme and test it out with a larger sample size, it would be nice to have some empirical data to back up his conclusion. Also he was testing it out against another player. I'm not a genius when it comes to these mathematical tests but doesn't it seem like the test would be most effective/relevant switching out hit gear against a level ?? mob?

Someone in the thread suggested this method of testing (emphasis is mine):

"If you want to do more testing, here's an alternative method...
Get a 60 mage with combustion and/or shatter and fight a lvl 66 mob. (Best to have a 70 tank it). A lvl 60 player has a 50% chance to hit a lvl 66 mob - with a few stacks of combustion or a frosbite proc/nova, the players crit rate is 50% or higher. On a one-roll system, a normal hit simply would not fit on the hit chart (50% miss, 50% crit, 0% hit) - ANY non-crit hit would be evidence of a 2-roll system."

If anyone has an old level 60 mage alt rotting away somewhere, this would be much easier to test than, say, going to ZG as a level 70 and swapping out mounds of hit and crit gear.

Actually I do have a level 60 Mage I could test this with. I'll try to run some tests on it tonight after a raid and see what stats I can come up with. Would it be easier to test with a non-binary spell, or a binary one? I don't quite think I understand what the original question about the 1 / 2 roll system was... I guess it doesn't really matter. I'll do some testing with both Fireball and Frostbolt.

EDIT: oh man, please delete, I'm inserting "not's" where there aren't actually any.

I notice that the front page of this discussion still cites the Blue Post for rating conversion info. Wouldn't it be better to reference the exact formula at 70:
[Conversion at 60] * 82 / 52

You will notice that all results round to the same numbers stated in the Blue Post to the accuracy they themselves noted, but that you get more accurate results. For example, the hit cap for rogues with 5% precision and Weapon Expertise is not 308.1, it's actually 307.5.

Using the exact formula was necessary to nail down the Weapon Skill vs. hit rating conversions.

It was also shown that fractional Weapon Skill rating is completely dropped in the calculations as 15 weapon skill rating which should give 3.8 weapon skill was shown to act as exactly 3.0 weapon skill instead. Maybe something useful to add.

I've noticed this rule being violated far too often, even here, so I propose it being added somewhere (either spellcasting or general, probably):
Multipliers are multiplicative. 10% and 10% is not 20%, but 21% (1.1*1.1). This makes stacking multipliers much more beneficial than is sometimes thought (i.e. shadow priest with full boss debuffs is ~+98% damage versus the +73% attained from adding). As far as I know, this is universal for all spell and damage school multipliers.

Careful though. You can multiply the wrong thing in some cases. I'm fairly sure it works in the way you describe for damage, but for threat, 10% reduction * 10% reduction != 21% reduction, but rather 19%, because it's actually .90 threat * .90 threat = .81 threat.

This isn't very useful if you don't have the level 60 conversion rates and that level of granularity isn't what I'm looking for here. I did add a note that they are rounded.

Too broad of a blanket statement for reasons posted above. It just isn't true for everything.

Druid threat bonus from talents?

"Empowered" type talents also add a percentage to the spell damage coefficient, rather than multiply the coefficient by a percent.

Is there any post-worthy information about the mechanics of using demoralizing shout on Boss mobs (essentially explaining the huge differences and useage between boss mob Attack Power quantities and player AP quantities).

Other than it's an observable drop in boss DPS, not really.

Actually, occasionally some multipliers are additive. For example, I've done some testing with the rogue talents, Surprise Attacks and Opportunity. I discovered that these 2 effects on Backstab are actually additive and not multiplicative for the bonus damage. This is just one example.

Perfectly understandable. The note is a good addition. My biggest pet peeve, (I mean no offense and applaud the work you are doing) is the 308.1 hit rating with Precision and WeX that should read 307.5 within the rogue section. The 308.1 was derived from rounded numbers. 308 is normally enough to avoid all misses (barring hit reducing effects) while the 308.1 number incorrectly implies that there is some value to a 309th hit rating under those conditions.