2pc damage for both our rogues yesterday hovered around 1.6-1.8%. Including trash mobs, it was even at 1.5%.
World of Logs - Real Time Raid Analysis , look for "Brennende Wunden", I didn't have the 2pc bonus until after Shannox.
I also just did some testings.
It will proc from: white hits, Mutilate, Backstab, Envenom, Sinister Strike, Main Gauche, Eviscerate, Gouge.
It will
not proc from: poisons, Rupture ticks, ranged attacks, FoK.
Maximum debuff duration is 6 seconds (3 ticks), which refreshes itself (Ignite mechanic, as mentioned before).
It also doesn't seem to crit.
// Edit: A running proc isn't affected by Vendetta either. The damage value, once established, is static.
Additionally, there is a severe bug with Mutilate double crits:
According to the mechanic description, it
should be dealing 6% of the total crit damage within its duration. It does so for white melee crits, but if both attacks dealt with Mutilate are crits (easily testable with Cold Blood), it bases off its 6% from the Off-hand
only.
An example:
My Mutilate crits for 17688 and 8250 (on a dummy). I see three
Burning Wounds ticks for 247 damage (one of them was actually 248).
Total damage dealt by Mutilate is 25938, and total damage dealt by the proc is 742. 742/25938 is actually only 2.86% instead of 6%. The ticks are all based on the Off-hand's 8250 crit (8250*0.03 = 247.5) instead of taking into account the Main-hand crit as well. The duration is increased, but not the damage per tick (it should tick for 519 instead).
It works fine for auto attacks, another example:
Crit 2461
Crit 2459
Tick 74
Tick 74
Crit 2494
Tick 99
Tick 99
Tick 99
2461+2459+2494= 7414
74+74+99+99+99= 445
445/7414= 6%
This seems to be an inherent bug with Ignite though, and not likely to be fixed anytime soon. The game code just doesn't handle simultaneous procs correctly ("Ignite Munching").
For references see here:
4.2 Changes Discussion
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