Maybe I have to add that I have the latest (stable) Arx Libertatis patch installed, but I cannot enchant this saber...

I've tried Amikar and Garlic.

Is this a bug or working as intended?

cheers

Seems these - like other "special swords" (meteor...) - can only be enhanced with poison, nothing else.

My guess is that items with special stat bonuses have already been enhanced in one way or another. I mean the Ciprian sword adds Strength and Constitution - there's no way for a piece of metal to do that without some megic trickery.

That's my conclusion as well; these are all magically enhanced swords; I truly wish one could make them indestructible anyhow, seeing as there are only a few stones in the world of Arx; but at least the best items already are indestructible :-)

Named items cannot be enchanted! Unless they are the unidentified armor pieces that special Ylside woman drops (hidden spell that summons a devil).