Originally posted here (with campaign idea uses): https://theotherside.timsbrannan.com/2022/10/100-days-of-halloween-coven.html

The Coven

PDF. 45 pages. Black & White cover and B&W and color interior art.

This is a 0-level or 1st-level "adventure". In fact the adventure covers creating a coven of new "witches" (1st level magic-users). There are a lot of random tables to help generate these characters including their background, patrons, enemies, and more for these witches. You also generate the lands and homes of these witches and their enemies.

This book is designed for Lamentations of the Flame Princess, but that is close enough to B/X that you can use that or OSE instead.

I say "adventure" in quotes because there is not an adventure here. There is a setup for future adventures and there are plenty of ideas here to create your own. But no "going to point A to point B and kill monster X."

What it might lack (and I don't think it is lacking) in structure it makes up for in style and detail.