Gunderholfen is a massive, old-school exploratory sandbox-style mega-dungeon and campaign setting published in 2019 by G. Hawkins. Spanning over 400 pages, this "vanilla" OSR (Old School Renaissance) adventure is designed for characters from levels 1 to 10+ and is compatible with systems like OSRIC, OSE, and B/X. Overview of Gunderholfen
Gunderholfen serves as a substantial, ready-to-run dungeon for D&D-influenced game systems. Its strength lies in its comprehensive, well-indexed, and modular structure, making it a reliable resource for both novice and experienced Game Masters seeking a long-term dungeon campaign. If you'd like to explore this further, I can help you find: A direct download link for the PDF. Specific reviews from users who have run this campaign. gunderholfen pdf
This is harder. PF2e expects tight math. Instead of converting each monster, simply find the PF2e equivalent monster (e.g., the "Ghoul" in Gunderholfen becomes the PF2e Ghoul). Use the PDF for the map and room descriptions only. Specific reviews from users who have run this campaign
Map Pack: Includes 40 high-resolution maps for the dungeon, city, and surrounding hexes. Summary Review Perspectives and Old-School Essentials.
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Gunderholfen is a classic megadungeon designed for character levels 1 to 10+. It is technically built for OSRIC (a 1e AD&D clone) but is highly compatible with nearly any OSR system, including B/X, Labyrinth Lord, and Old-School Essentials.