“ 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.”
“ The heroes find the crumbling, overgrown ruins of what appears to be some sort of grand dining hall in the forest. Deciding that it is a good place to camp, the set up a fire in the center. However, they are woken in the night to see skeletons waltzing in the moonlight to organ music that emanates from the open air. The skeletons touch nobody, dancing around them all night.”
“ An army and navy who work in the same way as others except their rank titles are upside-down. So people start as full generals and those with the rank of private command armies.”