Cthulhu Guard: The Inspiration

One roleplaying game I am particularly fond of is Trail of Cthulhu by Robin Laws and Kenneth Hite. It’s the perfect blend of old-school Lovecraftian horror with new-school rules, and its Gumshoe engine-based mystery clue mechanics are brilliant.

However, there are two things I am not particularly fond of with this game:

  1. I don’t care for how pacing works in Trail of Cthulhu. It uses a skill point pool mechanic that works excellently for extended game sessions, creating a feeling of building suspense and impending doom. But if you ever try breaking a mystery up into a few shorter sessions, you’ll quickly see the suspense factor only really comes into play when you get closer to the climax — which is a problem when a single mystery spans the course of a month. This also makes the game rather inappropriate for narrative Play by Post or Play by Email mysteries, which can take even longer than that.

  2. The game’s mechanics also don’t lend themselves well to improvisation, which is a GM style I particularly enjoy. There are some good tips for improv GMing in The Armitage Files sourcebook, but it still leaves a lot to be desired. It can be done, but it requires a GM who is really on their toes, with a very firm grasp of mystery story procedures. This can be tough to pull off for most GMs, especially when they’re having to deal with pacing issues on top of it all. 

On a completely different note, another game I really rather like a whole lot is the Mouse Guard RPG by Luke Crane. I’m a huge Burning Wheel fan (you’ll hear much more about that later, undoubtedly), and Crane really captures the essence of Burning Wheel in his ode to David Petersen’s graphic novel series (which unfortunately just had a TV series also based on it just get shelved). Mouse Guard is genius, so genius that I can run it rules-lite for my 3-year-old daughter.

Now of course, when I find an RPG mechanic I’m not satisfied with (ToC’s pacing issues and resistance to improv), I can never fight the urge to rules drift. And what better way than to combine it with some rules I really quite like?

That’s right.

I’ve created a mashup of Trail of Cthulhu with Mouse Guard that functions as a “frontend module” for Trail of Cthulhu. No, it’s not mice vs The Mythos. It’s 1930’s humans vs The Mythos, just like in regular Trail of Cthulhu, but it uses many of the Mouse Guard mechanics as a replacement for much of the core Trail of Cthulhu mechanics.

Yes: It’s crazy. It’s awesome. It’s been playtested. And it actually fucking works.

CTHULHU GUARD: THE INTRODUCTION

First off, Cthulhu Guard is NOT a standalone game. It’s meant to be a frontend for Trail of Cthulhu, replacing the first 81 pages of the player’s manual. The remaining 149 pages of that book are meant to be used in-game, and all of the official Adventures are compatible with Cthulhu Guard. That’s right: nearly 100% compatible. I actually playtested this game using The Armitage Files, a mystery campaign that is built specifically for improvisation, and it was super fun.

Which leads us to this mashup’s core strength: it’s designed to be very improv-friendly. It allows for plot to evolve out of the skill rolls and to be constantly centered around the PCs, just as in any Luke Crane-designed game. As long as the GM has a vague idea of how they want the mystery to unfold, the story just sort of falls into place like magic.

The other primary feature of this game is how pacing has been completely redesigned. There is no slowly diminishing skill pool like in Trail of Cthulhu. Instead, PCs have a very small pool of “free checks” that they can spend on investigative skills for free clue reveals. These checks are only replenished when the PCs traits come into play — just like in Mouse Guard 2nd edition, for anyone familiar with the rules.

Another large divergence from Gumshoe game design philosophy I have made is that I allow players to roll investigative skills for non-core clues whenever they want. This is a feature: Mouse Guard-esque consequences of failure drive the plot ever forward, and it places a greater weight of importance on the limited number of free checks players have access to. But of course, Core Clues are still freely given, as in every Gumshoe game.

Beyond this, I’m not going to explain how to play Trail of Cthulhu and Mouse Guard 2e because...I’m just not going to rewrite whole rules books. But also, this mashup is really only for people who own both books: I can’t write all the mashup mechanics out because that would be plagiarism, so I’m only going to tell you which parts to mash together and how. Kinda like sex ed. back in school, only more awkward.

To read the Cthulhu Guard rules, see this document.

If you don’t know how to play both ToC and Mouse Guard 2e, this doc will likely be gibberish to you. But fret not: I will soon be designing a brand new rule set for Cthulhu Guard that is inspired by ToC and Mouse Guard instead of just using those rules as written.

Until then, happy mashing.