Regardless the text on the card Spectre can be defeated using weapon without Magic trait. Looks as a bug.

 

Sorry if it was already reported and I missed it.

What weapon did you use to fight the Spectre, and what do you consider "defeated"? If you have won the combat without magic and the Spectre has gone back into the location deck, you haven't defeated it.

Were you in the forest?

Defeated - I mean that he doesn't return to his location deck. I used longsword or something similar, but without Magic word.

I don't remember about location, but I had the same effect more than once. I will check/remember the particular location and weapon when meet him next time.

The forest I believe auto defeat monsters regardless of you winning the combat check or not. And if you are using kyra she auto equip magic trait when doing combat check with undead.