[Icemage]

WARNING: If you hate math and research, stop reading this post right now.

Found some time yesterday to test out a theory which has lately been kicked around on some other forums. At the request of Jehryn(RDM75), who shows up here on FFXIOnline as Dakkon, I'm posting here the results of our test regarding various items which grant resistance to physical damage:

Test subjects:

Icemage WHM75/BLM37, wielding Earth Staff to tank.

Jehryn RDM75/BLM37, using various combinations of Earth Staff, Genbu's Shield, Cheviot Cape, and Jelly Ring

Target monster: Cactuar in Western Altepa Desert. Chosen specifically for its physical attack "1000 Needles", which always deals exactly 1000 damage, divided equally amongst all players/pets in range.

Item statistics:

Earth Staff: Listed as "Physical Damage Taken -20%"
Cheviot Cape: Listed as "Physical Damage Taken -5%"
Jelly Ring: Listed as "Physical Damage Taken -5%, Magical Damage Taken +5%"
Genbu's Shield: Listed as "Physical Damage Taken -10%"

At the time we tested, we also explored the theory which has been kicked around which states that Cheviot Cape has a hidden effect which gives it an additional 5% damage resistance during nights (in-game).

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The Theory: Jehryn mentioned that there are discussions which are being made on other forums (KI, Alla) that suggest that multiple -Damage% items do not, in fact, stack, but instead are multiplied in a "stepped" manner: i.e. the theory states that if you had the 3 items listed above, you'd take 20% off your base damage from the Earth Staff, then 5% off of what damage remained, then 5% damage off of what is left after those two were applied. I expressed doubts about it when he mentioned it, but I outline the basics of the theory here to facilitate discussion:

Damage calculation per "The Theory":

1000 Needles = 1000 damage / 2 players = 500 damage per player.

500 damage - 20% (E Staff) = 400
400 - 5% (Cheviot Cape) = 380
380 - 5% = 362 expected "theoretical" damage

Damage calculation per "common wisdom" which states that all damage% items are added together and calculated at the same time:

1000 Needles = 1000 damage / 2 players = 500 damage per player
500 damage - 30% (E Staff + C Cape + J Ring) = 350 expected common wisdom damage

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Testing Results (Actual damage, expected damage via common wisdom, expected damage via "The Theory")

(a) 20% Earth Staff only: 400, 400, 400
(b) 10% Genbu's Shield only: 451, 450, 450
(c) 5% Jelly Ring only: 476, 475, 475
(d) 5% Cheviot Cape (daytime) only: 476, 475, 475
(e) 10% Cheviot Cape (nighttime) only: 453, 450, 450
(f) 5% Cheviot Cape (daytime) + 5% Jelly Ring: 453, 450, 451.3
(g) 10% Genbu's Shield + 5% Jelly Ring: 427, 425, 427.5
(h) 10% Genbu's Shield + 5% Cheviot Cape (daytime): 427, 425, 427.5
(i) 10% Genbu's Shield + 5% Cheviot Cape (daytime) + 5% Jelly Ring: 404, 400, 406.1
(j) 10% Genbu's Shield + 10% Cheviot Cape (nighttime) + 5% Jelly Ring: 380, 375, 384.75
(k) 20% Earth Staff + 10% Cheviot Cape (nighttime) + 5% Jelly Ring: 330, 325, 342.0

Careful observation of the discrepancy between all 3 sets of numbers above will show that (a) there's definitely something wrong and (b) "The Theory" doesn't account for what's happening.

So what's really happening? Here's what we've come up with:

We think that Jelly Ring, Cheviot Cape, and Genbu's Shield do not fully live up to their promise.

Genbu's Shield: This item appears to give approximately -9.7% physical resistance, not -10% as advertised in its description.

Cheviot Cape: This item appears to give approximately -4.7% physical resistance during daytime, and -9.4% physical resistance at night, not the 5% as advertised.

Jelly Ring: This item appears to give approximately -4.7% physical resistance, not 5% as advertised.

Substituting these numbers into the above calculations makes them fit perfectly when using the "common wisdom" calculation (i.e. add up all physical resists and subtract them at the same time).

CONCLUSION

The common wisdom is right about physical damage effects stacking. However, certain items which reduce physical damage by a percentage do not give the exact amount that they describe.


Icemage

[Blood Red Poet]

/clap, spread the word.

[Hyrist]

Well done Icemage we appricate the data. Maybe we can get SE to correct its calculations or further more correct its advertisment of these items. It really seems strange that they would botch somthing like this so plainly.

Edit: Oh, and tell Jheryn I said Hi.

[neighbortaru]

very nice work Icemage and Jehryn! certainly very interesting to know. /praise

[Nodoka]

Icemage you're my hero. o.o

[Ka1'E1]

I wouldn't be too concerned that it is .3% off, I don't consider that "Botched". It seems to be a consistent .3 as well.

Nice work Ice

[TheGrandMom]

They probably rounded up is all. 4.7...nah 5% looks better and is easier to remember.

[grunion]

so cheviot does have -10% phys damage at night?

safe to assume the HQ is -12% i guess

[Ghostraven]

wowwwwwwwwww
nice work Ice, what you planning on testing next =D

[tdh]

Good work as usual Icemage.

As for the .3% difference, could that come down to job traits and/or Protect? Or was that considered and the 1000 Needles just ignores that ?

Just curious since it's such a small amount, perhaps there was something else there that boosted DEF. But good work!

[DakkoN]

Hyrist: Hi =x

Grunion: It -should- be 12%, but since the -% of Cheviot Cape is not what it says, I wouldn't be surprised if Umbra Cape is the same way.

tdh: 1000 needles is consistant, regardless of having Protect/Shell on. Ice rebuffed Protect/Shell when they would wear. As you can see from the numbers Ice posted, The only one that gave the numbers that it -should- have been, was my Terra's Staff. Projected: 400, Taken: 400.

[Icemage]

Should note that I recast Protect simply to increase our defense against the Cactuar's physical attacks to make my Stoneskin last a bit longer. Protect/Defense has no effect on 1000 Needles damage (only physical resistance and Phalanx seem to affect it).


Icemage

[Dragonsword]

Great job, Icemage, very useful information indeed. ^^)b

[Mila]

:bow: awesome work as usual.

[DakkoN]

There's some interesting discussion regarding this on Killing Ifrit. Couple of people not understanding that just because something is 'assumed' that it is 'fact'. I'm done trying to explain the point to deaf ears.

http://ffxi.killvoid.com/forums.php?m=posts&q=76852