Answers in red.So, just trying to understand:
If I have a level 20 fighter with capstone, or an opportunist Rogue (10%), wielding a T3 Epic Cutthroat Smallblade (6%) and a Epic Swashbuckler (6%), the intended total double strike chance is 22%. If the blade and the shield provide different bonuses, e.g. enhancement and competence
There might be a chance, however, that both "6% doublestrike bonus" in both items are scripted as the same, and do not stack, putting the combination into the 16% doublestrike chance. Not chance, but dependent on type of bonus
The same character dual-wielding T3 epic Cutthroat Smallblades would be surelly at 16% because it's not intended for the blades to stack with each other. Yep
The same character, wielding a T1 epic Cutthroat Smallblade (3%) in conjunction with either a T3 smallblade or swashbuckler would surely have 19% doublestrike chance because the effects are different.If you are using two blades, only the highest one will apply. If you are using the blade and the shield, provided that they have different types of bonus, they will stack, independent of bonus quantity. If the blade and the shield have same bonus type, only the highest one will apply