'Block Effectiveness' using the "The Slab" shield

[hypersot]

I'm trying to understand why this shield has 'block effectiveness' as a stat on it considering the fact that, on a block, the damage is reduced by 100% anyway.

What am I missing?

[Scipo0419]

It's not 100% damage reduction, it's 100% less damage.

If you take 100 damage at 100% damage reduction, you take 0 damage.
If you take 100 damage at 100% less damage, you take 50 damage.

The Slab reduces all incoming damage by half on block, it's just worded weird, the block effectiveness reduces it further.

My dumbass was using the "more" formula as referenced by psojed below. This formula would be: x/(1+y) where x = Base value and y = the increase in stats.

It's commonly used for "Cooldown reduction" which is obviously where I got my wires crossed. 100% Cooldown reduction leads to a "divide by 2" situation because you're increasing the amount you're reducing cooldowns by. Taking "less" damage, per The Slab, should be x/(1-y) or in this case, 0.

My guesses are that as Psykrom said, it's based on the block effectiveness cap, so you're only taking 15% of the damage, the devs applied the "more" formula because of "reduction" and the description is confusing, or it's hugged because it's using the wrong formula (see ballista situation for similar "the formula didn't match the description" bugs)

[hypersot]

ok, I was about to go to bed and feel a bit sleepy so maybe that's why I still don't get it.

100% less damage of 100 is not 50, it's 100.. If it was 50 it would have been 50% less damage.

I get it that it probably works as you say but saying 100% less of 100 being equal to 50 of 100 is just.. not correct I think.

Could you elaborate how 100% less equals to half of the damage?

Thanks

[Xorik]

The Slab should fully mitigate damage from hits. Idk what the first person is talking about cuz 100% means all of it. Posts from within the last two years mention it to ignore hits or treat it as "dodge" once you have block chance exceeding the penalty from The Slab. Block effectiveness is just there because the base shield as a non-unique had it in the first place.

[Psykrom]

Damage mitigation from block is max 85%. But reaching that number depends on your block effectiveness and the level area.

So possibly it would be 100% less damage calculated from 85% mitigation at most?

There's a formula too:
https://www.lastepochtools.com/guide/section/block

[Psojed]

Originally posted by hypersot:

100% less damage of 100 is not 50, it's 100.. If it was 50 it would have been 50% less damage.

I get it that it probably works as you say but saying 100% less of 100 being equal to 50 of 100 is just.. not correct I think.

No, he was wrong as the other poster suggested.

"Less" is a keyword. From the game guide
https://www.lastepochtools.com/guide/section/increased_added_and_more

More values are also percentages, so 1 is added each time. Less sources are also applied here as values subtracted from 1.

In this case, 100% less damage on block with Slab means:

X * (1 - 1) = 0

so you take no damage on block.

---

The reason it has Block Effectiveness is that every Unique item is a Unique version of a base item. The Slab is Unique version of Ironglass Shield, and every Ironglass Shield has the Block Effectiveness as one of it's affixes.

---

PS:

Originally posted by Psykrom:

So possibly it would be 100% less damage calculated from 85% mitigation at most?

There's a formula too:
https://www.lastepochtools.com/guide/section/block

Originally posted by Scipo0419:

My guesses are that as Psykrom said, it's based on the block effectiveness cap, so you're only taking 15% of the damage, the devs applied the "more" formula because of "reduction" and the description is confusing, or it's hugged because it's using the wrong formula (see ballista situation for similar "the formula didn't match the description" bugs)

The answer is in the links we already posted. From the block page:

Block is a defensive mechanic that grants a chance to reduce the damage taken from hits.

so Block mitigation is the "reduced" keyword.

Going back to my link, you'll see that "increased" and "reduced" happens before "more" and "less". Showing that in a simplified formula:

(X * (1 + increased - reduced)) * (1 + more - less)

So as you can see, the 85% cap exists before the more/less modifiers are applied. We already know that the resulit of the more/less formula is zero, so adding that in:

(X * (1 + increased - reduced)) * (1 + 0 - 1)
(X * (1 + increased - reduced)) * 0
= 0

So with The Slab, it doesn't matter what our Block Effectiveness is, or what the cap is, because the result is always zero.

[hypersot]

Thank you all. I never expected such an old post will finally get answered. So my thanks to Scipo0419 for pushing it to the top so it got the answers.

I always loved the shield as I love all uniques that really play in a 'unique' way.

Thanks again.