Glen Halstrom also has a review of the B2.5 Caves of the Unknown & its a solid overview of the module. But these are only some of the options for a dungeon master wanting to run some classic D&D elements for the Caves of the Unknown.
Instead since last year I was running
BEX1 Descent Into The Caves of The Unknown does exactly what it sets out to do & that is provide the players with a clean out module for this location but this is a deadly little romp. Don't expect a quick two game session. There is some actual backstory here & the caves are occupied by a deadly little band of monsters. The author provides monsters with motivation,reason, & really this isn't a bad little adventure as a side quest after B2 Keep on The Borderlands is done. If I start overgeneralizing BEX1 then I could potentially spoil the whole adventure but by all means if you want a good side quest for a B/X Dungeons & Dragons game then this might do for a quick side quest. The third option that I've used all of the way back in 2014 is the Caves of The Unknown done by the Breeyark! site as a part of the Project on the Borderlands . Makes sure to download & use the Cobweb Caverns as a part of the whole affair. This is a deadly little addition to B2 Keep on the Borderlands .
Another resource that I love to refer back to is the Zenopus Archives article on B2 Keep On The Borderlands. There is a ton of stuff here to pick & choose for the dungeon master to add spice to their version of the Keep.
Here are ten ideas for running B2 The Keep on the Borderlands By Gary Gygax:
- The keep was a military point for the struggle against the bandits who were backed by the slave lords & now the network is making headway into the borderlands once again. This is due to the elemental evil cults also helping to stir the pot.
- The keep is part of a net work of fortresses that were used by ancient armies and now the evil around them is brewing once again can the PC's help to turn the tide.
- There are a number of Lovecraftian evils that have been drawing the humanoids to the area. This option I used with Astonishing Swordsmen & Sorcerers of Hyperborea
- The caves of chaos are part of ancient machinery for the generation of humanoids & they must be shut down at all costs.
- Humanoid tribes are drawn to the caves by the ancient caves as a apart of a military rite and this will last for thirty days seeing the massive war against the human population. The rite must be disrupted.
- The lands around the keep are the breeding grounds to the ancient lizard men & this connects in with the N1 Cult of the Reptile God module By Douglas Nile
- There is an ancient lich or evil that has been trying to reassemble itself in one of the dungeons around the keep and its called back its army of humanoids to it. It must be stopped.
- The order of knights who once owned the keep are trying to raise the funds to try & buy the keep from the king. They hire the party to search the dungeons for their treasures!
- The keep is connected to the T1 The village of Hommlet because of the evil cults that one raised the land. The cults secretly have agents that watch over these places lest any good adventurers or knights begin to take back these places. These cults are funded by the slave lords.
- These keeps & castles of Greyhawk guard the planes against planar marauders & the like but haven't been used in eons so they've fallen to evil.