# How do attacks work in Diablo III?

Does Diablo 3 use a single-roll attack table, or does each possibility get rolled separately.

For instance, on a single roll table, any given attack has X% chance to hit, Y% chance to crit, Z% chance to be dodged, and A% chance to be blocked.

The alternative is a cascade, where each possibility is tried in order. I.e., Was it dodged? No, then was it blocked? No, then did it crit? No, so it's a normal hit.

Gearing strategies change a little depending on which method is used, so I was hoping someone could shed some light on this.

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Why would it change? (X * Y * Z) = (((X) * Y) * Z) – ayckoster May 17 '12 at 16:40
@ayckoster the one uses a single random number. The other uses a new one each time. – Raven Dreamer May 17 '12 at 16:51
@ayckoster because in the former, the percentages are capped to 100%. This means it is possible to push possibilities of the table. If you have a 30% chance to hit, 10% chance to crit, but 70% chance to be blocked, a single-roll system would mean you have a 70% chance to be blocked, and a 30% chance to hit, and since the crit has been "pushed off the table", you can never earn a critical strike despite ostensibly having a 10% chance. – Raven Dreamer May 17 '12 at 17:21
I do not know what they use, but what you propose is wrong math, as Instead of 100% there would be 110% which would cause every percent value to be wrong. I believe Blizzard has accounted for this, even if they use a single roll table, thus the effect should be the same either way. Still, if you want to know how the system works your question is legit :) – ayckoster May 17 '12 at 17:31
@ayckoster Just because you don't understand what I'm saying doesn't make it wrong math. I'm talking about an Attack Table, not a strict percentage. – Raven Dreamer May 17 '12 at 17:34

Click To Loot's Combat Mechanics Compendium, among other sources, seems to suggest a two or possibly even three roll system, in which Dodge and Block are both checked separately from an attack roll. As far as I know, there is no concept of an attack 'missing' in D3. If the projectile makes contact, either it is avoided via Dodge, mitigated by block, or it does 'full' damage (reduced by Armor/Resistance as appropriate).

Regardless, this becomes impossible to test until it becomes possible to approach 100% Crit through gear. In general, mobs do not have a particularly large amount of dodge or block, so it's probably not possible to perform any sort of reliable testing without modifying game files (not happening) or an expansion that introduces large amounts of MUDflation (highly unlikely anytime soon). That said, if it's not possible to test, it's also not possible to build a gear set where that fact is relevant, so the point is largely academic.

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I have yet to see an attack "miss" during my playtime (200+ hours). – kalina Jun 7 '12 at 11:31
@ickleislands Agreed. The key question is whether there's any analog to the mechanic of 'glancing blows' from WoW, some portion of whatever combat table that can never become a crit. Given the existence and effectiveness of Sharpshooter, this seems unlikely, but it's not really viable to test it now, and is largely an academic exercise anyway. – LessPop_MoreFizz Jun 7 '12 at 11:34
I take that back, it's possible for mobs to miss you. It shows no text. Tested by logging a level 60 into normal mode, first quest of act 1 (The Fallen Star) and standing between zombies. When they miss you, your character appears to flash white briefly (split second). With this in mind I wouldn't discount the possibility of a partial hit/glancing blow. I'd also suspect that the combat table contains the following; miss, hit, dodge, block, crit, glancing(possibly) – kalina Jun 7 '12 at 13:34

Experienced speculation is that it's how you describe a 'cascade'. From a programming standpoint it makes the most sense to do it this way.

Here's how I would do it: A: Negate all attacks (y/n), B: Dodge (% based), C: Crit (% based), D: Block (% based) E Damage calculation from all base and modifiers.

As far as I can tell, this is also how the mechanics function in game.

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Except that that would be inconsistent with how Blizzard has historically handled attack rolls in most of their systems, so your 'experienced speculation' isn't worth much unless you have some evidence. – LessPop_MoreFizz May 26 '12 at 12:38