In the Eastlands, it's Labyrinth Lord btb.

 

Two characters per side, four per sheet, good for NPCs as well as PCs.

 

E1. The Ruined Keep of the House of Fauus
A Labyrinth Lord (basic D&D) adventure. It is an introductory dungeon for 4 to 6 1st level beginning PCs.

 

E2. The Halfling Horrors
A Labyrinth Lord (basic D&D) adventure for 4-7 1st level PCs.

E3. The Chambers of Ancient Mystery
A Labyrinth Lord (basic D&D) adventure for 4-7 1st level PCs. Tables are given for stocking on the fly. Inspired by, and including elements generated from, a terrific series of posts at http://aeonsnaugauries.blogspot.com/