I am curious are these just encounters or mini-adventures? For example is it something you throw into a larger module? or is it more like a quick one night game?
Thanks.
It can be either, really. I guess I would describe it as a single encounter location expanded to short adventure level detail. For example, the Dark Elf Sanctum is really just one room (the cleric's bedchambers being ajoined). But there is a lot going on in that one room, and the bedchamber really just serves as a starting location for the cleric, who will enter the main sanctum shortly after the PCs.
There are suggestions for how to expand the encounter into more of an adventure (an encounter for on the way to the Sanctum, and a "what's next" section following).
I posted a review for Dark Elf Sanctum over at EnWorld, there is some more info there.