In the last few days I fight with Shadow Dragon (I can't spell his name from memory) and Firkraag, and both of them seems to detect invisibility even from the begining of fight. I did not see them casting True sight or something like that, but they saw and atacked me if I was in shadows, invisible or improved invisible.
The same problem was with the liches from Temple ruins (solo, high level ...). They refuse me the pleasure to backstab them.
Has anyone more information about it?

No idea about the dragons, but get yourself some protection from undead scrolls and you can backstab, frontstab, or even give a big sloppy kiss on the mouth to those liches.

I solo'd through there with a high level monk, & counted on MR and low saves. Dragons got a quivering palm in the viscera.

It is true, there are some monsters with innate ability to see through invisibility...e.g. dragons,liches,Kuo--Toas...

As was said, several monsters can see through invisibility.

Also note that some monsters are immune to backstab, e.g. Beholders, you will get a message "the backstab seems to have failed" in those cases.

Dragons do see invisible creatures, but that ain't the cause why backstab always fails with them. Only humanoids can be backstabbed, and dragons aren't humanoids at all.

SWORD SPIDER!!!TSSSSSSSK!!!

[This message has been edited by TIN_MAN (edited August 08, 2001).]

I backstabed Spiders, Umber Hulks, Spore colony and another weird creatures, who are not humanoids. AFAIK beholders, dragons and golems could not be backstabed.

In order for Backstab to work your character would have to be able to hit a vital spot, Dragons are so large that they are immune to backstab.