I believe It actually stacks, but since I am not allowed to post in DM's answer/questions this'll have to do!

I was asking about Damage Immunity though.

Barbarian immunity -will- stack with item immunity.

I've tested this not only on other servers with a barb/wizard build, but in single player.

Unless EFU has changed the way Damage immunnity works. It will stack.

Are you sure you're not thinking about the high-level Barbarian damage reduction feats?

Damage immunity is the thing that comes in percentages. For instance, damage immunity Cold 50% will half any cold damage you receive.

Damage resistance subtracts the damage from the total amount. For instance, damage resistance 10 will render 15 damage as 5 damage.

I don't know if EfU has many damage immunity items (I've never seen one), but damage resistance is there. The barbarian thing is also damage resistance. 1 point without any magic rating, I believe.

And, yes, damage resistance does stack in NWN. It's not supposed to according to core rules, but it does.

Damage immunity probably doesn't stack (to be quite honest, damage immunity in percentages is rather rare on any server as far as I know), but that's not the way it's supposed to be working anyway. I mean, two 75% damage immunity items would equal 50% absorption. Lol, overpowered.

Damage resistance items at least don't stack. Nor does a tiefling's fire resistance stack with any fire resistance items.

Against, Barbarbians on EfU get 10% damage IMMUNITY. And I have an item with 10 or 5% immunity for various physical damages.

This topic is an excellent example of why you're not supposed to ask mechanics questions in the DM Q&A forum except for very specific cases.

Resistances do not stack (5/- electrical + 5/- Electrical stays 5/-)

Damage Immunity stacks up until a full 100% (5% Damage Immunity + 10% Damage Immunity vs. Bludgeon damage will become +15% vs. Bludgeon damage)

I'm absolutely certain.