I think that direct elemental damage is not counted as magic.  Of course, ophidians are immune to dragon breath, so who knows.

I have a gut feeling that at some point the developers took a shortcut and did not bother clearly differentiating between a physical attack, physical special move, mundane ranged attack, ranged ability, spell, and spell-like ability.

These things ALWAYS come to bite you in the ass.  If dragon breath is indistinguishable from a fireball (and it should be different) and if a thrown knife is a spell, there's something wrong.

The game's definition of magic is quite narrow. As far as i can describe it, "magic" is effects caused by a spell, which is selectable as an action in combat, and falls in the "spells" category of the tactical combat skillbar screen.

Elemental damage which does not come from a spell, isn't considered magic. even if it is quite clearly from an enchanted staff throwing magical bolts of fire.

I'd agree that the current way it works is illogical. But how SHOULD it work ?

re magnar: They have a negative resistance to the element of cold, and are weak to alll cold damage, whether it's from a spell or not.