Do ability boost from different enhancement trees stack?

[Bolo_Grubb]

So if I took the 2 intelligence boost from the assassin tree and the 2 intelligence from the mechanic tree, would I get a total of +4 to int?

[ZeebaNeighba]

yes

[Plantman81]

I thought this to be true, but when I respec'ed my wizzie to take both intel points from the AM tree AND the PM tree they did not stack as expected. I previously was pure ArchMage with only the 2 pts of intel from that tree. After respeccing to access both sets of inel increases my intel did not go up. Surely this is not WAI?

[Inoukchuk]

I thought this to be true, but when I respec'ed my wizzie to take both intel points from the AM tree AND the PM tree they did not stack as expected. I previously was pure ArchMage with only the 2 pts of intel from that tree. After respeccing to access both sets of inel increases my intel did not go up. Surely this is not WAI?

I'm not 100% sure they stack if from same class, but I've tested and confirmed they stack from trees in different classes.

[TPICKRELL]

I'm not 100% sure they stack if from same class, but I've tested and confirmed they stack from trees in different classes.

The WIS from monk Shintao and Ninja trees definitely stack or at least did when I reset enhancements a few weeks ago.

[ReaperAlexEU]

my mechassassin has exactly that, +4 INT from both trees combined.

i think all ability ranks stack from all trees, it's non-ability stuff that doesn't stack, like critical accuracy.