Shadows of Yog-Sothoth

This is a Call of Cthulhu 7e long-term campaign with a cast of 4 regular characters and a couple of guest appearances. Our four primary investigators are Gambler, Museum Curator, Animal Trainer, and Asylum Attendant. We also briefly had Pilot and Detective, but for scheduling reasons both were unable to stay in the group past the prologue. We played about twice a month, for around 2.5 hours per session.

Shadows of Yog-Sothoth is an early 6th Edition campaign, but I converted it using a combination of the rules from the 7e Keeper’s Handbook, as well as the Malleus Monstrorum and the Grand Grimoire of Cthulh Mythos Magic. The latter two texts are not necessary, but they do make the conversion faster and easier.

Prologue: Arkham

As is often the case in older campaigns, the introduction to the story is rather artless and abrupt, so to smooth the way and allow the characters to develop, I first began with a reskin of Crimson Letters. I envisioned a locked-door whodunnit, which is why Crimson Letters was an attractive entry point, but the challenge was to mask the original scenario adequately, since Museum Curator and Pilot are both seasoned Keepers and would recognize the plot too quickly if it wasn’t disguised properly. There was also the matter of leaving enough clues to solve the introductory mystery without revealing everything, and also creating a reason for the investigators to care enough to jump off into the main plot once they’d concluded with the prologue. 

I first began by starting in an Arkham entirely of my own imagination, based very loosely off the map provided in the back of the Keeper’s Handbook. In order to make Crimson Letters work for me, I decided to keep the setting of academia but pivot to a more glamorous donor gala at Miskatonic University (what good university doesn’t honor their donors?). I liked the idea of winter so that investigators who had invested in tracking and nature skills could use them, and also because it presented an environmental danger for the investigators if things got out of hand. Having invented a gala, I then needed a building map and approximately 20 original NPCs and the main NPC who would bridge the gap between the prologue and the main campaign: Carl Stanford.

Once I had created the NPCs, the building layout, and the layout of campus, I turned to the Crimson Letters plot. Crimson Letters presents multiple possible characters who could have stolen the important documents that starts that scenario’s plot. These documents are not important to the reskin, but the idea that there were documents stolen I liked as a red herring. 

The idea that slowly coalesced was that Carl Stanford was part of the Hermetic Order of the Silver Twilight (HOST) and had essentially been a sleeper agent, working quietly in Arkham as a history professor until called into action. In the interim, in order to fund HOST’s activities abroad, he worked an extremely successful antique restoration scheme, processed the money through a fake bank account under a fake name, and sent the money abroad to Scotland. When called into action, he needed a no-questions-asked getaway, and so he began manufacturing the idea that he was a pathetic drunken gambler in steep debt and the antiques scheme was a way to pay off that debt. He wrote fake journal entries wherein he appeared to go through a downward spiral from which he couldn’t escape and which grew darker and more paranoid the longer it went on. He also created the idea of a staff feud with one of his fellow professors over the idea that he was stealing and forging documents.

When he was finally called back to HOST, Carl Stanford faked his death. He acquired a body from far outside of Arkham, staged a crime scene, left incriminating evidence of his debts to others, and even left a convincing forgery of the Roanoke Colony Charter in the office of the colleague with which he had a “feud”, with the idea of framing her for his death. Then, with the help of fellow cultists, he made good on his escape, using the gala as a high-profile distraction while he flew back to HOST headquarters. The prologue picked up at the gala, hours before Carl’s “body” was discovered and the investigators were pressed into service. 

The party was extremely thorough and weren’t really tricked by the various red herrings for more than a session or two. They doggedly followed leads and spent many hours in-game and out discussing possibilities and pitfalls and examining the plot from multiple angles.

As the scenario progressed, homebrew elements were created as needed, including every handout in the prologue and a number of backstory, B-plot characters and elements. I didn’t want to overcomplicate the prologue though, because I wanted them laser-focused on Carl Stanford, his deception, and creating stakes high enough to justify them pursuing the mystery to Boston.

One of the things I had to create was a jail scenario in case the investigators were found meddling in the case by law enforcement. For this, I used the 1st edition scenario The Madman, which, with very little retooling, could implicate the Arkham sheriff instead of a random person, and could easily take place on the top of French Hill. The fact that Ithaqua could potentially be summoned was a nice little coincidence given that it was the dead of winter; thankfully, it never occurred.

All-in-all, the party finished the prologue in 7 sessions.