Energy Shield % increase on amulets broken?

Hello,
I'm trying out a CI witch and I noticed that the % increase amulets I have (i.e. 17%, 18% increase) don't seem to make much difference. Amulets with +17 energy shield and 20 intelligence (so another 5 to es?) seem to have a much bigger increase. Or picking up a 6% ES passive on the tree.

I haven't really investigated this to give you hard numbers, but I was surprised by the lack of statistical impact trying my amulets on had on my character's ES.

Is there something about the mechanic that's different for amulets and for "+X to Energy shield" when it comes to % ES increase?

Winterlude

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winterlude wrote:

Amulets with +17 energy shield and 20 intelligence (so another 5 to es?) seem to have a much bigger increase.

Somewhat expected, especially if we're talking about Werma (your characters are hidden right now)

"

Or picking up a 6% ES passive on the tree.

Strange, shouldn't be happening

"

Is there something about the mechanic that's different for amulets and for "+X to Energy shield" when it comes to % ES increase?

Yes, absolutely

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tl;dr available at bottom of post
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The way "x% increased anything" in Path of Exile works is that it stacks additively with other existing increases. This results in a lower multiplicative change (multiplicative is "x% more") from your current net (total) value of, in this case, ES.

Example of diminishing proportional returns (constant, linear returns technically) on "x% increased":
Suppose you have 100 base (flat) global ES. (This value isn't displayed on any character sheets). Then you add a total of 50% increased, from the tree or whatever:
100 * (100+50)% = 100 * 1.5 = 150 net ES.

Then, add 50% increased on top of that:
100 * (100 + 50 + 50)% = 100 * 2.0 = 200 net ES.

Note that 50% increase, or "and a half again," applies to the base value, not your previous net value. that is, 150% * 150 ES = 225 ES. That's what you would get with "more," or multiplicative stacking.

The base global ES is based on flat ES from your gear, tree, and skills. They are all added together. For main pieces of armour (chest, hat, gloves, shoes), local increases from modifier stack multiplicatively with the base ES value of the item type to yield the amount of flat ES added to global ES (so a chest with 100 ES as a white item, and a +100% increased ES mod, will grant 200 flat ES to the global value). (In this way, "local ES%" acts like a "more modifier," but of the base ES. You don't need to worry about these details if you ignore flat ES on main pieces of armour and instead read the blue value near the top of the item.)

+ES on Jewelry adds directly to base global ES.

x% increased ES on Jewelry adds to the global increased ES multiplier.

You are likely to have a large existing increased ES multiplier from your Intelligence and passives. For this reason, supposing you see on your screen, say, 100 ES, it is easy to believe that 18% increased energy shield could give you much less energy shield than +17 ES. Why? Suppose you have existing 50% increase from Intelligence and passvies. With a bit of algebra-jiggery, that works out to 66 or 67 base global ES (i.e., the sum of the blue figures on your main armour pieces, plus any flat from jewelry or passives)

Adding 17 to that is about a +25% change, or "25% more." (17/66 = 25.8%) That's already more than 18%.
(You can do the full math as follows:)
(66+17) * (100 + 50)% = 124.5

Adding +18% increased ES yields:

66 * (100 + 50 + 18)% = 110.8

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As you can see, it's definitely possible for +17 flat ES to be better than +18% increased ES.

TLDR in POE, like most RPGs, you need a mix of flat value and multipliers (or different multipliers) to get a big value. You can't readily convert from flat to multiplier without knowing math details

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winterlude wrote:

Hello,
I'm trying out a CI witch and I noticed that the % increase amulets I have (i.e. 17%, 18% increase) don't seem to make much difference. Amulets with +17 energy shield and 20 intelligence (so another 5 to es?) seem to have a much bigger increase. Or picking up a 6% ES passive on the tree.

I haven't really investigated this to give you hard numbers, but I was surprised by the lack of statistical impact trying my amulets on had on my character's ES.

Is there something about the mechanic that's different for amulets and for "+X to Energy shield" when it comes to % ES increase?

Winterlude

INT gives % increase to ES btw, so 20 would be 4%.

I just did a test and the amulet is working properly.

Also, it depends on the gear and tree but the flat ES will give more in certain situations.

100ES x 1.18 (amulet 18%inc) = 118

(100ES + 17) x 1.04 (amulet +17ES +20INT)= 123 (rounded up)

Dammit if I knew somebody else was replying... :)

Thank you for your replies.

It's my understanding then that to calculate total ES, there are three parts:
1) % increase (1 per 5 intel), passive %, jewelry %
2) flat (armor, passives, gems (discipline) and items that add ES)
3) more (15% from infused shield behind Chaos Inoculation)

I've tried to use the formula: 1+% increase x flat x more = ES... It's not working out perfectly (I'm probably overlooking something), but it's in the ballpark.

Thanks again for the assistance!

Winterlude

"

winterlude wrote:

Thank you for your replies.

It's my understanding then that to calculate total ES, there are three parts:
1) % increase (1 per 5 intel), passive %, jewelry %
2) flat (armor, passives, gems (discipline) and items that add ES)
3) more (15% from infused shield behind Chaos Inoculation)

That's it. You add up your flat ES from gear and discipline, then you increase it by the % increase from passives and gear and intelligence (if you have 2k base and 280% increased ES, the calculation is 2000 + 2000*2.8), then you multiply the final result by 1.15 for CI.

There's a niche scenario with ES shields and the 'increased defenses from shield' stat which is worded ambiguously. It increases the ES you gain from the shield but this additional ES does not benefit from other increases (i.e. from %increased maximum ES).

Okay, thanks for the advanced tip about the "Energy Shield on Shield" passive. I was considering picking up the shield node, but my shield is only 270 ES with maxed quality and no crafting option, and I'm not sure if the shield block is worth it either.

Winterlude

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winterlude wrote:

Okay, thanks for the advanced tip about the "Energy Shield on Shield" passive. I was considering picking up the shield node, but my shield is only 270 ES with maxed quality and no crafting option, and I'm not sure if the shield block is worth it either.

Winterlude

It isn't. Block works only when stacked in large quantities.

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winterlude wrote:

I was considering picking up the shield node, but my shield is only 270 ES

"Only" 270 ES??? 270 ES is an amount you can be REALLY proud of for a shield! Honestly, you likely won't find one with a higher value anytime soon. If I had such a shield, I would make sure to get that node...
You would get a boost of around 124 to your ES with that node. (Math: (270*0,4)*1,15)