I was drawn back into Call of Cthulhu when one of my friends started running one-shot adventures for his teenage son. Suddenly, even old, barely-remembered adventures like The Haunting were magical again, and we were all having a blast tromping around abandoned cabins, fleeing cultists and Deep One-infested lighthouses, and laughing as we inevitably went crazy and died horribly (and in one instance, vice versa). I was inspired to write my own Cthulhu-esque adventure, and set myself four goals:

1. Historical setting. I love the limitations of the 1920s in Call of Cthulhu. Even more, I love that as you go further back in time, communication gets harder, weapons get less effective, help is further away, and people become more superstitious. I’ve always loved the Old West as a setting, so I picked 1883 and a remote, dusty location for the adventure, set between Kansas City and Arkansas City.
2. Scary and Unheard Of. I always enjoy adventures where the big bad is something unpredictable, unknown, and freakish, and can’t be easily found flipping through a Monster Manual or Lovecraft compendium. So I spent a few hours researching Native American mythology to find something that I had never heard of, and would surprise my players. I settled on the wonderfully strange, cannibalistic Teihiihan as my foes.
3. Multiple Threats, Multiple Tools. My own favorite horror adventures are the ones where the PCs are faced by tough odds from different directions — vs a single monster or bad guy driving the threat level. I spent some time thinking about multiple physical threats (the Teihiihan, a wounded and betrayed outlaw), environmental threats (the scorching desert, the caves themselves), and mental threats (the bodyswitching plot of Rufus and Hoowooni). I also enjoy adventures where tools can be found, but not always needed, so I made sure that there were always hidden supplies (bear traps, unpredictable flintlocks, books with legends) available — but never necessary to finish the story.
4. Make it easy to run. I did my best to surround the adventure with lots of handouts, premade characters with good diversity and motivations, and optional encounters for GMs who want to customize the adventure, or shorten or lengthen it.

The adventure resonated. The PCs’ health (and sanity) was whittled away over the first half of the adventure, motivating them to keep moving. They figured out Hoowooni’s weird plot in the last half, made it to the final encounter in the mine, and then everything went to hell due to poor planning and worse luck. I think only one or two survivors limped back to civilization… which was everyone’s favorite way for a one-shot horror RPG to end.

The Durned Flaws

All adventures have flaws, and The Black Mine of Teihiihan is no different. If I spent some time revising it, I’d make some changes:

1. Works Best in a Certain Order. It’s possible for
   PCs to skip Dunker Cabin and head right to the further-south Fort Rufus. While
   this doesn’t derail the adventure at all, I suspect the mystery would be harder
   to solve, and the PCs would certainly have less tools to survive. I’d advise
   GMs to plant a few more clues on the way to Fort Rufus, for those survivors who
   decide to skip the cabin.
2. Hosaa is Too Important. Hosaa, the Arapaho
   medicine man, is a bit too convenient, showing up a the perfect time to fill in
   the gaps in the story and push the PCs towards the Black Mine. If he gets
   killed or the PCs mistrust him, the adventure could possibly stall out. In
   retrospect, some more self-contained clues about the Black Mine, either at Fort
   Rufus or Dunker Cabin, would help give the PCs more agency.
3. PC Relationships. The pre-made
   characters are literally “Strangers on a Train” with no connection to each
   other. While this setup works fine with players who love to slow down and
   roleplay, newer players, or players who need some help meshing with each other,
   could benefit from more concrete, in-character reasons to interact. GMs who run
   this adventure might give some of the characters familiarity with each other.

That sums up design and execution of The Black Mine of Teihiihan. You can download and give it a try here:

• The Black Mine of Teihiihan (GURPS Old West)
• The Black Mine of Teihiihan (GURPS Old West) – Printer Friendly
• The Black Mine of Teihiihan (Call of Cthulhu)
• The Black Mine of Teihiihan (Call of Cthulhu) – Printer Friendly
• The Black Mine of Teihiihan – VTT Assets & Tokens

Anniversary Update: The Black Mine of Teihiihan has been one of the most popular adventures on the site. I’ve also run it several more times since the first time. To celebrate its anniversary, I’ve updated the adventure. Not only are some of the issues mentioned above fixed, but I’ve also clarified some sections, added bookmarks, included two new battle maps in the VTT assets, and, for GURPS players, include GCS files in the VTT assets so GMs can import them into their VTT of choice. Enjoy!

If you run the adventure or play in it, all that I ask is that you let me know what you thought and how it went… especially if you get blown up by your own stick of dynamite in the mine. Post a comment below or tweet me @SageThalcos

Related: More Historical Horror – Terror in Ancient Rome