I've been reading through the Call of Cthulhu adventure collection Mansions of Madness, Volume 1: Behind Closed Doors, and this is my review of the third scenario, called The Code. I also reviewed the first scenario, Mister Corbitt and the second, The Crack'd and Crook'd Manse. There are no spoilers beyond what you'd read in the introduction to the adventure in the book. If you're thinking of playing an investigator in any of these scenarios then even that might be too much, so this review is intended for game masters.
The Code seems like a classic mansion adventure, but it's got a surprise twist (for the players, at least.) It reads like it would be a nightmare to run, but the authors devise a clever system the game master (er, Keeper) can blame any apparent inconsistency on. In the adventure, the investigators are summoned to the home of a physics professor, Dr. Kenneth Connolly, one of them has a connection to. In the letter, Dr. Connolly warns the investigators that his lover, Lizzie, and her brother David, are not to be trusted.
When they arrive, they're greeted by William Fetter, Dr. Connolly's servant and groundskeeper. William takes them inside, where they learn that Connolly has invited along 3 other friends: Dr. Quinn of Harvard, Miss Carlson of Miskatonic University, and Claire Whitley from the University of Chicago. After introductions are done, William Fetter rushes back into the room, saying he can't find Dr. Connolly anywhere!
The rest of the adventure is about figuring out what's happened to Dr. Connolly, and maybe more importantly what strange experiments he's been working on within his mansion.
OK, I'll say it. There are too many names in this adventure. I don't mean too many people, I mean too many names. Some of the NPCs go by different names than how they're introduced, and other NPCs are apparently optional and can be used as spare player characters (which I definitely think is a mistake, because in a mystery you want some spare suspects). Write the names and universities down early, and bring your cheat sheet to every game session. You will need it.
There's a mechanism in the game where clues about what's really going on are delivered through what the scenario calls anomalies. It's a very clever system, and combined with the strange nature of Connolly's experiments it makes it easy for you to drop in weird surprises to either help or hinder the players, or just mix things up. Whatever happens, you can just blame an anomaly, and beautifully it all makes sense in the end.
I do think the adventure plays with set a dangerous precedence, and I can't imagine running it as part of a campaign. I guess you could let the players play around with some of Connolly's work for a wee while, and then just destroy the experiments, and I think you'd have to, unless you really want to run the rest of your campaign where fundamental laws of physics are inexorably altered. I guess if I can run D&D with a character who has the Wish spell, I can run Call of Cthulhu with game-changing physics.
I feel like this adventure is the best use of a mansion in the book so far. The house has 15 or so rooms, and while it's by no means a dungeon crawl but an actual mystery, the list of anomalies ensures that any room can become interesting as pacing demands.
I appreciate that everything the investigators need to start solving the mystery is available from the start of the adventure. I don't mean that everything is in plain sight or is as it appears to be, but there's no big reveal at the end that keeps the investigators from, well, investigating. Yes, there's information the investigators must uncover, but it's all in the mansion for them to discover.
It's also got the classic you can't get out mechanism, like Clue (the movie, I mean) and Evil Dead and probably a bunch of Agatha Christie novels (which I ought to know better.) Once the investigators arrive at the mansion, they're pretty much there for the duration. By the book, their car won't start when they try to leave, but you could just as easily arrange it so that they're dropped off at the mansion. Mix in a thunderstorm for atmosphere, and you've got a pretty good mansion mystery on your hands.
Reading this adventure makes me realise that sometimes what I want in an RPG is a simple mystery, like Cluedo except fun. Even with the board game Mansions of Madness, some of my favourite adventures are low-combat and high-investigation. This adventure isn't actually that, and it features a healthy dose of the Cthulhu Mythos (and other spanners it throws into the works), but it's got the right veneer.
This is a fun scenario to both play and run, and its story leads to some real surprising developments that then escalate quickly. It somehow manages to contain some really big fictional tropes into a pretty simple adventure, without ever allowing things to spin out of control (unless you and your gaming group want them to.)
Table and coffee photo by Freddy Castro and licensed under the terms of the Unsplash License. Modified by Seth Kenlon, with a book cover featuring artwork copyright by Chaosium.