Shield mastery, increased defences

I have been working with some shield builds and I have no idea if this is the intended behavior or not but the added defence node for shield seems to be working like this.

normal armor calculation
base armor * (1 + increased armor / 100) * (determination for example)

but when we add the shield mastery is does not add to the "base armor" but instead
gets added before "determination kicks in" but after increased armor has been applied.

So if you have a shield with 100 armor after any quality and increased armor on the shield itself, you will get 30 armor added if you have a shield keystone with (30% increased defences) and this value is NOT going to be increased by "increased armor"

normal armor with icnreased shield defences calculation
(base armor * (1 + increased armor / 100) + shield def * (1 + increased shield defences)) * (determination for example)

It just seems that 30% increased defences on only one item compared to 10% for all items seems low since you have 5 pieces with the shield, but may very well be something I am missing.

This is from testing with armor/evasion shields and I might be wrong but if anyone could confirm or deny by findings I am happy : )

Last edited by devmoon on Dec 2, 2012 8:13:53 AM
Also wondering how this works.
it's base armour * (1 + all "% increased modifiers") * (1 + " % more modifier)" * (1 + " % more modifier) ....

all "increased" (and "reduced") modifiers to one stat stack additively. "more" (or "less") is used for those that stack multiplicatively. This is true for all stats in the game.

both "increased armour" (such as from passives) and "increased defences" are "increased" bonuses applying to your amrour value. Determination is a "more" bonus.
so the amount of armour from your shield is:
base shield armour * (1 + increased armour + increased shield defences) * (1 + determination)

Note that increased armour mods on the shield item itself are modifying the base armour of the item, not the armour you get from it, so are already applied before we get to this point, to actually get the "base armour" value.
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Last edited by Mark_GGG on Jan 14, 2013 5:58:55 PM
For additional clarity, does "Increased Defences" apply to every defensive stat? In other words, does it increase all resists, block chance, evasion, energy shield, etc?
"Increased Defences" affects only armour, evasion and energy shield.
Thanks QPic!
I think Zakaluka was going to show these nodes are mathematically inferior to most other defensive nodes, at some point? Maybe he found out they were actually good.
My Keystone Ideas:
Ofcourse a 30% Increased armor is better than 30% increased shield defenses as the armor node affect's all pieces of gear (including shield?) whereas he shield defenses node only modifies shield values.

But, consider that 30% armor nodes are rare, they are big nodes whereas 30% shield defenses nodes are common small nodes.
Gyeff // Greff // Gyaff
Yeah, but a single 10% armor node is already 1/3 of shield defenses, and it increases ALL of your gear's armor. Is +20% of your armor >= +20% of all your armor added together? I suspect not, though there's a bit of math involved for a large array of items. These calculations are a little bit different for hybrid shields and es (es is only +6% per node).

But hybrid passives, 8% armor / 6% es AND 8% eva / 6% es are probably better than 30% defenses from a shield.


I'll do a little math here:
Copper Tower Shield (lv 24): 199 armor; this is a pure armor shield with lower block chance, a "best" case scenario

Executioner's Casque (lv 26): 113 armor
Bronzescale Gautnlets (lv 23): 67 armor
Plated Greaves (lv 23): 67 armor
Warplate (lv 21): 154 armor

This isn't counting armor from belts (which can get a little high towards the end game) or other gear and passive/active skills, but those are effected too, while shield defenses is not.

113 + 67 + 67 + 154 = 401 armor
Shield = 199 armor

1.1 * 401 = 441.1 armor = 40.1 armor gained
1.3 * 199 = 258.7 armor = 59.7 armor gained

So increased defenses for your shield is better than a pure armor passive, when we don't include: Granite Flasks, Molten Shell, Belts, certain uniques. This analysis also doesn't take into account mods on gear; I believe these items all have the same +flat and +armor% mod possibilities, but if they don't, that's another factor.

However, in the case of armor/es nodes... if we use the same theory, I think armor/es nodes do win out, because the notable nodes of +20% armor/+20% es give the clusters of those nodes a much greater impact on your armor alone than shield defense nodes, which are less abundant.

It's worth noting though, clearly shown from the math above, that any armor node that gives over +15% armor is more or equally valuable/useful/worthwhile even when not considering belts, compared to +30% shield defenses. Adding another 5% makes 401 armor beat out 258.7 armor by 1~ armor.

Notable nodes that only give 20% increased shield defenses and +block chance are not that powerful, by the way, compared to pure armor nodes, because 1.2*your shield is almost equivalent to +10% armor, but actually weaker than it. Consider the notable nodes that only give 20% shield defenses and +block to just be over-glorified block nodes. They aren't that good especially when you consider how unimpactful pure armor is. For ES/Evasion, it's a little better, but even so.
My Keystone Ideas:
Last edited by anubite on Jan 15, 2013 3:00:03 PM
Wait, from that calculation, it looks like the 10% armor passive doesn't raise shield armor?
I understood that it doesn, but only stacks additively with increased shield defenses.
So shouldn't it be 10% of 600 = 60?
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