Read alot about some shields and puncturing strikes doing more damage than intended.
So I decided to test it myself.
Here are the results, including test numbers below.
Abilities found bugged so far:
Hardened ward, steadfast ward (and morphs), dampen magic, puncturing strikes (and morphs)
+25% dmg vs fire for vamps
+% healing (from champ or skills)
Abilities with +percentage increase tested and not affected by bug (working as intended):
+% dmg from champion lines.
+% resist from champion lines
-20% aoe dmg from blade cloak
Crystal fragments (the proc), might of the guild passive, reverse slash (and morphs)
-15% dmg from dizzying swing (minor maim)
+x% dmg from racial
dawnbreaker+60% dmg vs vamps
+10% invisible dmg from racials.
Untested:
Reactive armor set -35% dmg taken when CC'ed. This might end up at effective 15% dmg taken (50% reduction battle spirit+35% reduction from set)
Weird results:
Blade cloaked target hit by puncturing strikes. blade cloak effect calculated first then puncturing strikes modifier added after. 50% pvp dmg, reduced to 40% dmg taken with blade cloak up, but 140% modifier added=180% dmg taken.
Test results if you like to check the numbers yourself, bugged skills only because I'm lazy:
Hardened ward tooltip value 3986 in cyrodiil. Tooltip value in pve area 7972. Actual value 6617. Basically cyrodiil value is pve area tooltip value *0.33+cyrodiil tooltip value. It should be cyrodiil tooltip value *1.33=5301. Basically 25% more shield due to bug.
Steadfast ward tooltip 1540 in cyrodiil. Actual value varied from 9024 to 10318. This is due to steadfast ward scaling all the way down to 1% hp.
Basically the calculation is the same as for dampen and hardened ward. Actual value is up to pve tooltip value * 3+cyrodiil tooltip value. This also indicates a bug in the tooltip saying its increased up to 300%. The actual increase is up to 200%, or another way to update the tooltip would be to say its value was 300% of base value.
Dampen magic tooltip value 4506 in cyrodiil. Tooltip value in pve area 9012. Actual value 8291. Basically cyrodiil value is pve area tooltip value *0.42+cyrodiil tooltip value. It should be cyrodiil tooltip value *1.42=6398. Basically 30% more shield due to bug.
Puncturing strikes tooltip value: 440. actual damage 836. It should be doing 440+140%, so 440*2.4=1056*0,5 battle spirit=528 dmg. But instead it does 440*1.9=836 dmg (damage after battle spirit=0.5+1.4 modifier= 1.9 total modifier. or 58% more damage than intended.)
Vamp damage taken from lightning/cold force shock 440
vamp damage taken from fire force shock 660
Basically 50% more damage taken. Note that tooltip is 25%, but calculation is base dmg taken in pvp 0.5+0.25 vamp vulnerability=0.75 dmg taken in pvp. This is 50% more than the 0.5 dmg taken other players get.
Note on live we also take exactly 50% more damage from being vamp. Calculation is base dmg taken 0.8+0.4 vamp vulnerability=1.2 dmg taken in pvp. This is 50% more than the 0.8 dmg taken other players get.