can anyone confirm this? I'm sure the same thing occurs with other traits as well.

seanw3, you could be plenty plainer. I agree with the OP, it needs rewording. Adding "in addition to <previous trait level>" would do fine.

the first one says 50% MORE damage, and it's not made clear that they stack. That is my point

Ya, what's throwing me off is that when you get Evoker II or III. It replaces the previous version. I'm sure they do stack, but it's not too clear.

It should be written like this cause the higher level ones hide the lower level abilities.

That would be more confusing because people will think they are getting another 150% spell damage on top of the +150% they think they already have. If every upgrade is +50% there's no question at all that it's adding 50% more damage. They wouldn't give you a trait that does nothing, so there's no question that it stacks.

Once you already get the trait though you should be able to hover over the icon on the left and see the combined stats of all the stacked traits in that line.

Evoker: +150% spell damage

-----

Evoker 1: +50% spell damage

Evoker 2: +50% spell damage

Evoker 3: +50% spell damage

A simple "stacks with previous level of this skill" in the tooltip would clear the whole confusion up. There are probably other traits that could stand to have that tool tip as well.