Where do you get this infro from, pls link.
The ability as described ingame
Warmaster:
"has a 60% chance of inflicting bonus Damage when attacking. --------. Bonus Damage can only occur once per skill and does not count as an extra hit."
Giantslayer
"has a 30% chance of inflicting bonus Damage when attacking. --------. Bonus Damage can occur on each hit of a skill, but does not count as an extra hit"
Now In the wording it says specifically "Bonus Damage" Can only OCCUR once per skill not, this does not suggest that it only can have a chance to proc once. the way its worded makes it seem like it would be 60% on the first hit then if it does not proc would roll again on the second hit as that would not violate the condition of the damage only occuring once. now that would be harder to code and possibly not how the game handles it i just cant seem to find any official source on the matter.
personally in my experience of watchign my CB team my 2 hitter with Warmaster occasionally procs on the secodn hit and not the first, perhaps i am mistaken but this would imply that it would roll again on the second hit if the first one fails, would love a statement from plarium or someone who colleted alot of data on this, say ran a coldheart on CB and recorded all procs of warmaster, if the value is 605 with a far sample size then ofc it would be the 60% once per skill.