With lvl 5 armor upgrades and lvl 2 gallente LLAV I had -37% armor damage on a bare limbus, then I leveled the LLAV to 3 and still had -37%. My guess is the limbus has a default -25% armor damage, armor upgrades gives -10% and, only the first lvl of gallente LLAV works giving -2%, instead of -6%.

you know i think i got it. first the LLAV has 25% (both gallente and caldari) then 10% from skills then the LLAV skill is messing up giving another 10% w/o being based on the skills. and that would give the 37% base. but without anything from CCP this is all just a guess. can you tell me what resistance is w/ 2 passive 15% mods.

With lvl 5 armor upgrades and lvl 2 gallente LLAV I had -37% armor damage on a bare limbus, then I leveled the LLAV to 3 and still had -37%. My guess is the limbus has a default -25% armor damage, armor upgrades gives -10% and, only the first lvl of gallente LLAV works giving -2%, instead of -6%.

-37% is correct. When adding damage resistance, it isn't literally adding it up. Your damage resistance is 1 - [ ( 1 - .25 ) * ( 1 - .10 ) * (1 - .06) ] = .3655.

Where .25 is base resistance, .10 is Armor Upgrades V, and .06 is LLAV III. In words, stacking resistance only applies to what's left over, so two 50% resistances won't equal 100%, but 75% (50% and then add 50% of the remaining 50% to get 75%).

Hope this helps!

I don't think this is the case because when I had LLAV II, my armor resistance was still 37%. With that formula I should have had 35.2%

To answer lad war I have 53.43 with 2 x 15% armor mods.

Maybe someone with different armor upgrades and gallente LLAV lvls could share their stats.