I never did find one, so I figured I'd try to compile at least the basics. Then hopefully, it can be filled in by people who know more than me. Primarily interested in PvE.

Magical combat (I play a Mage, so this side is better):
Base spell hit chance = .96, .95, .94, .83 against level 60,61,62,63 mobs.
Base spell crit = Int/59.5

Is the crit roll before or after the hit roll? In other words, is my average spell damage (before resists) given by H*(1+C)*D or by (2C+H*(1-C))*D?

Spell damage = TooltipDamage + (spelldmg)*X
X is a scaling factor for each spell, generally given by max(1,CastTime/3.5). Instant spells have a cast time of 1.5, and channeled spells and DoTs receive the full value, divided over all the ticks. For AoE spells, multiply by 1/3. Sometimes, multiply by yet another factor for spells with secondary abilities (for example, .95 for Frostbolt).

Avg mitigation due to resists (whether spell is binary or partial): .15*resist/casterlevel. (not really sure here, but I'm assuming this goes linearly up to the cap of .75 at resist=5*casterlevel)

Mana regen per tick = 13 + Spi/4 (13 + Spi/5 for Druids)


Melee combat:
Base hit chance = .95*(something to do with weapon skill?). .76 if dual wielding.
Base crit chance (%) = 5+Agi/20 (/29 for Rogue?)
Ranged: 5+Agi/53
(Is crit chance then modified by defense and weapon skill, or just defense? Maybe something like (WepSkill-Defense)/25 ?)
Same question as before about crits--when are they rolled?

AtkPwr = 2*Str (1*Agi for Rogue?). Is there a base AtkPwr before stats and item bonuses are factored in?
RAP = 2*Agi?

Damage: Weapon Damage + AtkPwr*Speed/14 (replace Speed with normalized speed for instants)

Presumably, Dodge, Parry, and Block all stack multiplicatively. Where to they fit into the order of operations? (and how does Str affect Block?).

Armor mitigation = A/(A+85*AtkrLevel+400)

This is a good idea. I really hope to see it fleshed out.

FYI Druid AP = 2*Str + Agi

Rogue AP is just Str + Agi.

Really nice thread. I'd also like to know the order of operations on defenses.

To my knowledge, every point of defense you have above your opponent's weapon skill reduces crit rate by 0.04%, and increases dodge/parry/block chance by 0.04%.

Conversely, each point of weapon skill you have above your opponent's defense increases crit rate by 0.04% and reduces dodge/parry/block chance by 0.04%.

For tanking purposes: (Need to track down numbers on crushing/glancing, which become possible with a 3+ level difference in PvE.)

Re: your question above, "Same question as before about crits--when are they rolled?":

Hit/Crit/Miss exist in parallel and are rolled simultaneously. It is not two separate checks. Imagine that the game does a /random 100 every time a physical attack occurs. There are two relevant values: C and H. If you roll less than C, you will crit. If you roll higher than C but lower than H, you will "hit". If you roll higher than H, you will miss. By default, C is equal to 5 and H is equal to 95 against a same-level mob when not dual-wielding. For a rogue, H is equal to 76.

Now, imagine a rogue who has a 35% crit rate and absolutely no +hit whatsoever. C = 35 and H = 76 for him. 35% of his attacks will crit, 31% will "hit", and 24% will "miss." 53% (35/66) of his attacks that actually do damage will be crits, which may make observers say "wow that's an insane crit rate" but it's only looking that way because he's missing so damn much. Am I correct in believing that if you have absolutely no +hit at all, nor precision, a Cold Blood Evisc or other special can still "miss", despite the +100% to crit?

So, +hit gear converts what would have been a miss into a hit.
+crit gear converts what would have been a hit into a crit.
There is no way to convert a miss into a crit.

Other things we should get: Rage formula for damage taken and damage dealt (how does it relate to level?)

Yes, any ability used in Conjunction with Cold Blood can miss, however rogue instant-attacks have a base accuracy of 95% (as though not dual-wielding), even though both hands suffer a -24% from dual-wield. The dual-wield penalty applies to all classes, too, I believe, so hunters and Fur warriors also have a miss rate of 24%.

Wodin tried to explain rage, and after hitting me repeatedly with big fancy chains of numbers, I was able to grasp it a little:

Rage from damage taken: level*1.5=1, so 90 damage at level 60 gives 1 rage, 60 damage at 40, etc.

I don't remember the damage dealt algorithm, though. I think it may have been something like Damage/level, but I think it was a bit more complex.

Huh. So my avg. damage per cast is just given by (H+C)*D.

Among other things, means I was wrong to think that +hit gear was better for my avg damage than +crit.

Crit gear, in general is better than +hit, but that's in part due to a +hit plateau. It's wholly impossible to get 100% crit rate, however once you get more than about +10% hit you're wasting slots that could be better used by loading up on AP, crit, agility, stamina, etc. Hit gear definitely is helpful, but it's only good to a point since you can't hit more than 100% of the time.

Ok, I just did a bit of testing on a warrior. (He's level 12, so forgive the tiny numbers.)

It appears to be something like: (level*0.5)/damage

For example, most swings were doing 30-32 damage, and earning 6 rage.

+1% hit will turn one frostbolt out of a hundred that would have done 0 damage into a frostbolt that does X damage.
+1% crit will turn one frostbolt out of a hundred that would have done X damage into a frostbolt that does 2X damage.

Both are adding the same amount of damage. I think +hit is better for PvE since crits generate multiplied aggro (bad) and +hit also helps with things like resisted polymorph/banish, which +crit obviously cannot do.

I remember hearing, ages ago, that crits generate a disproportionate amount of aggro, but don't really know where that idea came from. Anyone have any details on this?

Lots of testing.

A crit generates a random amount of extra aggro, that averages out to around 50% extra. I think it's something like 133%-167% of the aggro the attack should generate, in my experience.

So if you crit one shadowbolt for 2000, that generates an average of 3000 aggro.
If you cast two shadowbolts for 1000 each, that generates 2000 aggro.

Incidentally, is there a way for me to be able to edit my own posts?

Ok, so I can't go back and continually update the OP with information?

Better stuff on AP:

160 + 2*Str (at lvl60), for Warrior, Paladin
100 + 2*Str, for Shaman
100 + Str + Agi, for Rogue, Hunter
100 + 2*Str + Agi for Cat
160 + 2*Str for Bear

How about RAP? Is it just 2*Agi for everyone (except wand users)?
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On crit chance:
Blizz has said that all classes gain Agi/20 crit, except Agi/29 for Rogues, and Agi/53 for Hunters. Does this apply to both melee and ranged crits for all classes? (i.e. do Rog/War crit at Agi/20 with guns, and Hun at Agi/53 in melee?).
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As far as I can tell, a 63 mob crushes your 60 tank at 15%, regardless of defense (for practical purposes).
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How do defense and weapon skill affect hit chance? Apparently defense makes you get missed more often. How does skill play in?
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What's dodge/parry/block chance?
Something like 5 + (def-wepskill)/25 + Agi/20 ?
(well, Agi/14.5 for Rogues and Agi/26.5 for Hunters)
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According to the post linked on the Warrior forums, Dodge, Block, Parry, and Miss all stack additively. This is not what I would have guessed, but makes a bit more sense once I've seen how they've handled hit and crit. Can anyone confirm?

Yeah, it looks like offensive Rage generation is 2*damage/level, while defensive Rage generation is (2/3)*damage/level.

From http://www.wowwiki.com/Formulas:Rage_generation:

RageForHitting = damage / (0.5 * level)
RageForGettingHit = damage / (1.5 * level)

So at level 60, 30 damage dealt = 1 rage and 90 damage taken = 1 rage.

Unsure if this is computed before or after armor.

There may also be a base amount of rage generated per hit (like 5 or so).

It would be nice to have section on threat generation too.

Assuming an arbitrary scale of 1 hate = 1 damage, how much hate does healing generate (I believe it's on the order of of .6 (and lower for Paladins)).

Is there a good table of threat values for various abilities, which is somehow referenced to damage aggro? I've seen a table or two, but they seemed scaled pretty arbitrarily, and may be out of date.

Finally, are we all agreed on how Taunt works? Permanently generates enough aggro to catapult you to the top of the list?

Rage is calculated after armor both on the giving and the receiving end. Hence warriors complaining about being rage-starved at Onyxia.

One thing I'm unsure of: does +spell hit only affect fully resisted spells? This has implications for binary spells like frostbolt, where you would be able to stack more +hit and still get a benefit than you would if you were casting fireball, since the miss range would extend.

For example, let's say your fireball hit distribution looks like this:
1-80: 0% resisted
81-85: 25% resisted
86-90 50% resisted
91-95: 75% resisted
96-100: 100% resisted

If +hit only affects full resists, then stacking more than 5% would be of no benefit. Compared to frostbolt against the same mob (assuming equal fire and frost resists), the distribution might look like:

1-90: 0% resisted
91-100: 100% resisted

I'm unsure of the exact mechanics for resists and binary spells, but I think it would work something like that. Anyway, here you can stack up to +10% hit and still see a benefit.

Does anyone know how this works exactly?

Okay, so they're not crazy.

Genjuro, those are two separate mechanics.

There's a level-based check and a resist-based check (which gives you your partial resists, or most of your full resists vs. binary spells).

+spell hit reduces the number of level-based misses
The resist-based misses/reductions will only occur when your target has a nonzero level of resistance to the element you're using. In 1.9, spell penetration will mitigate that.

It's not quite like that. Magical combat is actually quite parallel to weapon combat--there is both a "hit" roll and a "mitigation" phase. The "mitigation" component is based on the target's resists in this case, however, and is also all-or-nothing roll in some cases (unlike weapon combat, where mitigation is constant).

It's just confusing for casters because a "miss" and a successful saving throw both appear as "Resist."

Against a 60 mob with 200 Frost resist, my hit chance is 96% and his mitigation is 50%. My Frostbolt will land 48% of the time. With +hit gear, it will land 50% of the time, but not more.

Thanks, that makes a lot more sense now and puts spell penetration into perspective for me.

Edit: I assume that the level-based mechanic scales in the same way as for melee, as in base chance of 5% and the faster dropoff at >= 3 levels? I remember back in CB when you actually had the number next to your spell school, like Frost 270 much like weapon skill. Too bad they hid that that, it would give them an option for +frost skill or +fire skill items as another option for item stat allocation.