SEALED INSIDE is a simple system-neutral one-shot and dungeon generator made from the Lesser Key of Solomon. It's simple. Your party will become CULT HUNTERS. Choose a cult. Choose the Duke they are trying to summon. Choose one or more dungeon maps the party will explore to find both cult (first) and the Duke (second). There are many more options in this book like possible motivations for your party as well as additional creatures, traps, and treasure. Ultimately, this book is a utility for you to use as you see fit. It also pairs very well with the Beneath series.
Use an RPG system you’re comfortable with. And also roll in creatures and NPCs as you wish. Each cult has guidelines for rolling in preexisting creatures and how they may be affected or mutated by the cult.
Small gray stars on the maps represent where you can generate creatures, NPCs, traps, or treasure. Choose one of these stars to signify where the cult is performing their summoning ritual. Larger hollow gray stars are where the Duke is.
You can also use a D60 to randomly generate the 60 dungeon chambers. D60s are easy to find online if you need one.
That’s really it. Use this book for a one-shot or have your party come back six times to hunt all six different cults. The party can even carry over items from the previous hunt so the adventure compounds.