Well, I played on RZ on live for about 4 years, and one thing that was always used was jousting as Puella said. Most of the time the rogue can run at the other person and hit backstab at just the right moment, and be considered behind the other person even if they were facing eachother. This was a tactic used mostly when melees were fighting eachother, but also when casters that had damage shields were fighting melees (except monks/warriors used 2 handed weapons as I stated earlier). Yes I know this isn't live, but you are also forgetting that melees have been given an increase to damage done in pvp, which would probably raise the amount of damage done per backstab. Now, also I believe rogue's have a style that allows them to double all damage they are doing for a short amount of time. Now I know that you cant always use this style, but if you do 600 damage per backstab on average in pvp, and you use this style, you would in turn be doing 1200 damage per backstab. Now, my level 65 druid isn't uber or anything, hes about average. He currently has about 2.2k hp self-buffed, maybe a bit more than that. If you backstab him for 1200 damage, he can heal it relatively quickly, but that means that in the time that he is healing you are most likely hitting him, which leaves room for interuptions as well as your backstab refreshing. You also have to remember that you do have the ability to 1 hit him with a backstab (either your max BS + crit, or your max backstab + style, or max backtsab + style + crit = almost instant death). I also am aware that instead of instantly healing I can snare/root you or do some other tricks to get out of range but I am assuming worst case scenario where people panic.
I honestly don't think that damage shields being as high as they are (I think druid Relic DS is 48 or so? and I doubt most druids probably wouldnt have Relic DS so what is the next highest 38?) is that big of a deal, and there are ways around it. But like I said earlier, its really not that big of a deal, since it wont effect the majority of the people here anyways. I dont really care what happens, I just dont want to see something nerfed for no reason, and because people can't be bothered to work around something.
Toodles, Jinxat.
EDIT: I also forgot to mention chaotic stab. I don't really know how effective this is, but I think it allows rogue's to backstab from any angle. Anyways, there are ways around the "damage shield" issue, and I think that taking away part of the druid's utility would be kinda crippling to the class form a pvp standpoint.
EDIT: I also forgot to add druid's self damage shield line. At level 65 this would add another 20 points to the damage shield according to the spell database (I am not completely sure if this number is right) . Now a 58-68 point damage shield could be considered overpowered, but most of the time I doubt druids would have buffed using both unless they were anticipating pvp (I think I have casted the spell once since I dinged level 65). Never the less, the damage shield could still be somewhat avoided, it would just make the rogue want to make sure that his hits are worth it.
