I'm not sure even ZOS can answer this question.

Weapons should provide fixed values instead of % based increases.

@Asayre Page not found

Yes, works now.

Consider that atm some stuff is bugged.
Poison damage for example uses armor penetration for skills but spell penetration for some DoT effects and weapon glyphs.

Mix wrote: »

Asayre wrote: »

There are two kinds of penetration, percentage and flat. The formula for mitigation is

Examples of percentage penetration include Sharpened, Nirnhoned, Penetrating Magic, Heavy Weapons for Maces and Twin Blade and Blunt for Maces. Examples of flat penetration are Concentration for Light Armour users, Spell Erosion and Piercing. At V16, your level is 66.

The base percentage penetration is 0 and the base flat penetration is 100.

where did you find that the base flat penetration is 100?

edit: since v1 and 50 are the same level (ie. your character goes from level 49 to v1), wouldn't v16 = 65?

Everything in the game, players and mobs, all have 100 base penetration.

For most mechanics in the game, 50 and V1 are treated as separate levels in the formulas.

Grr, okay but I cannot get any of this to line up with my empirical testing.

I removed all points from Concentration. Moved 100 points from Elemental Expert into Blessed to act as my CP baseline, 0 in Spell Erosion. Equipped a Precise staff instead of nirnhoned. I used Molten Whip as my test spell as it is simple direct dmg on target. So Spell resist in this case, may only be Fire resist for that mob, since I only tested Fire dmg.

Tooltip of Molten whip stated 6150 damage. Character has no spell pen, so just base 100 according to you guys (did ZoS tell us that everything has 100 base spell pen?)

We can assume if a mob has 0% Fire Resist that Molten Whip will do 6150 damage. (I did find if I stacked enough spell pen and major breach I could take most of my target mobs to 0% resist and Molten Whip would hit for 6150 damage, but never any more than that.)

Thus, I concluded that the different in damage between the Molten Whip tooltip and the actual amount it hit a mob for would equal its spell resist. I'll give two example mobs: Giant which has lower resist and Dwarven Spider which has really high resists, v16 Wrothgar mobs, outdoors.

Giant: Molten whip hit for 5043; 18.000% dmg resisted
Dwarven Spider: Molten whip hit for 3924; 36.195 dmg resisted

I then applied Major Breach using the spell Elemental Drain, tooltip states this reduces a mobs spell resist by 5280.

Giant: MW hit for 5692; 7.447% dmg resisted
Dwarven Spider: MW hit for 4573; 25.642% dmg resisted.

Then I took the original dmg resist and subtracted the dmg resist with Major Breach:

Giant: 18.000-7.447=10.553%
Dwarven Spider: 36.195-25.642=10.553%

From this I concluded that 10.6% = 5280 spell resist rating(the amount removed from a mob by Major Breach)
Thus, 1% spell resist = 498 spell resist rating.

To find the resist of the Giant and Dwarven Spider I then took their resisted % from the first test and multiplied by 498 to get:
Giant: 8964 Spell Resist (Fire)
Dwarven Spider: 18025 Spell Resist (Fire)

If I take your formula and work backwards though, knowing that for the Giant 18% of MW damage was mitigated. I have no %based spell pen on and only the base 100 flat spell pen. If I solve for spell resistance:

(0.18)(66000)+100 = 11980 spell resist.

but the predicted mitigation after adding major breach is:

((11980-5280)-100)/66000=0.1 or 10% mitigation, but I actually saw Molten Whip dmg decreased by 7.447% not 10%.

Gonna stop here, but I did tests with varying combinations of Nirnhoned, 100 Spell Erosion, 2/2 Concentration and Major Breach.

Could you please explain why my results aren't lining up?

Ah, thank you! @Asayre

Now to go over the rest of the tests and see if they fall into line as well:)

It's not quite clear to me why you conclude that spell erosion is broken.

Spell Erosion works the same way on PTS and Live it's just that the tooltip in Live is extra confusing. On Live, 100 points of Spell Erosion gives 1980 flat penetration. One way to interpret the Live tooltip is that it gives x% of 120*Level (7920 at V16) flat penetration. I believe this is what you are referring to in your first sentence. I'm not sure why you are dividing 1976 by 25% though. Could you elaborate on that part?

On the PTS, the flat penetration offered by Spell Erosion is just the tooltip amount. On PTS, 100 points of Spell Erosion gives 5281 flat penetration.

From post #14 in this thread, you estimated the spell resistance of the Dwarven Spiders to be 18200. From this all your data appears reasonable to me.

No spell erosion, Live


100 spell erosion, Live


100 spell erosion, PTS

SkylarkAU wrote: »

Asayre wrote: »

There are two kinds of penetration, percentage and flat. The formula for mitigation is

Examples of percentage penetration include Sharpened, Nirnhoned, Penetrating Magic, Heavy Weapons for Maces and Twin Blade and Blunt for Maces. Examples of flat penetration are Concentration for Light Armour users, Spell Erosion and Piercing. At V16, your level is 66.

The base percentage penetration is 0 and the base flat penetration is 100.

Thanks for sharing this info. I'm quite keen to understand how things are working under the hood, is there a website that makes all of this stuff available?

Also, what would be an example of an armor debuff?

Major Fracture. Major Breach. Mark Target.

Asayre wrote: »

Sorcerer Arithmagic has most under the hood ESO equations, @SkylarkAU.

Many thanks, I'll check it out!