“ Small identical wooden or metal discs with a strange pattern engraved upon them (do not appear to be coinage). The discs can be found all over the continent; a farmer typically overturns several dozen when ploughing a field. Though they are unnaturally hard to break, they have no known use and are widely used as good-luck charms: almost all households would have them on the doors and on mantle pieces; many people carry one or more on them, bound on to a belt, necklace or sewn on to their clothes.”
“ A certain type of demon cannot not be hit by ranged weapons or attacks. Attacks have to be made up close and personal for the damage to mean something. Ranged attacks are to impersonal.
Possibally a way to make the ranged attacks more meaningful would be to coat the arrow head or what not with the shooters blood. Of course, they'd better be a good shot, otherwise they're wasting arrows and already bleeding to boot.
Spells: wizards might have half or no effect, preist might work due to divine intention.”
“ A casual remark by one of the party about something met on a previous adventure leads to a summons to and grilling by the Mages' Guild (or equivalent), probably resulting in an expedition back to that area to recover the things for study by the Guild. The party's presence will be 'requested' for this expedition.”