The Armitage Files is Robin D Laws’ groundbreaking adventure of improvised Mythos investigation.

Cthulhu Confidential is Robin D Laws’ groundbreaking game of solo Mythos investigation.

Putting two groundbreaking products together is hazardous for Gamemasters. You run the risk of collapsing the ground beneath you.

However, the risk can be worth it: improvised play supports the deep investigative dives of one-on-one play.

Improvising On The Run

In a Trail of Cthulhu game using the Armitage Files, the Keeper can take advantage of the times when the players are arguing or speculating amongst themselves to plan ahead and decide on what the players might find when they follow the next clue. While the players argue whether or not they can trust Austin Kittrell, the Keeper feverishly reads over the Sinister and Stalwart versions of the Kingsport Yacht Club that Kittrell mentioned and decides which incarnation the players will encounter.

There are few such downtimes in one-on-one play. You can stall the player by giving them a handout such as a new Armitage Letter, but mostly the game will be relentless investigation and action. (There’s a reason that Cthulhu Confidential scenarios tend to be longer and more intricate than regular Trail games.) The best approach is to study the Armitage Files material thoroughly in advance, internalising it as much as possible so you can decide on the fly to connect the Yacht Club to the Nophru-Ka Panel, which of course means a visit to the Anthropologist and he can see invisible horrors clinging to the investigator which means you’ll need to set up an invisible horror encounter before the player gets there…

Sketch out potential plots and connections in advance. Identify (or ask your player) which clues are most likely to come up in the next session, work out two or three follow-ons from each clue and then pick the most appropriate one in response to player decisions. It’s a gamemastering high-wire act.

Where possible, bend the plot around the protagonist. The Armitage Files includes several handouts that reference player characters by name (Document 3, Document 4, Document 6, Document 9) – but is otherwise light on personal connections to the investigators. After all, in a regular Trail of Cthulhu campaign, there’s every chance that one or more investigators will perish before the end. That’s not the case in Cthulhu Confidential, so take advantage of the protagonist’s privileged status to ensure that the mystery revolves around them. (For those fill-in-an-investigator’s-name gaps in the handouts, put the investigator’s name in one of them and fill the others with Sources and compelling GMCs.)

Look For Solid Ground

Cthulhu Confidential uses cards to track Problems and Edges and to give detail and texture to the character’s experiences. Instead of just losing four Health, the investigator might have been Clawed by a Deep One or Punched by Butcher Brown or Fell Down A Hole – each of which causes an injury, but has different consequences and solutions. In a regular scenario, these cards can be designed in advance because the GM knows the likely encounters lying ahead. In an improvised campaign, this approach is reversed –  design the cards, and then improvise encounters that lead to those cards. For example, if you’ve prepared the Fell Down A Hole problem or the Mob Tie edges, then look for ways to push the protagonist into a pit or get a favour from a mobster. Prepare a stack of Problems and Edges in advance and look for ways to bring them in (start with the Mythos Problems articles by Robin, as well as the Generic Edges and Problems in the Cthulhu Confidential appendix and build from there.)

Of course, improvised games always include unexpected events, so have a stack of blank cards to hand that you can fill in when warranted. Mark important plot twists and consequences by turning them into Problems and Edges.

For Problem cards, include specific ways to remove each Problem. For Edge cards, note exactly what benefit it gives and when it can be cashed in. Be as concrete as possible – if that Mob Ties edge gives you a bonus when dealing with mobsters, then that’s a prompt for the Gamemaster to include some mobsters to justify the Edge’s existence. (Improv thrives on constraints and prompts.)

Problems and Edges usually arise as a result of challenges; have a copy of the Challenge Difficulty table on p. 45 of Cthulhu Confidential to hand while running the game.

The Armitage Sources

The various academics and scholars in the Armitage Inquiry make excellent sources for most topics. Between them, they cover virtually every academic investigative ability imaginable, with non-academic assistance provided by the redoubtable Mrs. Pickman and Dr. Sprague. With so many professional abilities available through sources, the obvious route for the protagonist is to concentrate on practical investigative abilities like Streetwise and Evidence (although any of the usual Cthulhu Confidential protagonists could be used in an Armitage Files campaign by transplanting them to Arkham country.)

Dreadful Correlation

To reiterate – running an improvised One-2-One game isn’t easy. Don’t pick up the Armitage Files and assume that you’re good to go. In a conventional improvised campaign with multiple players, the Keeper has a whole group to riff off and steal ideas from. Here, it’s just you and one player, alone in a whirlwind of possibilities. Running this sort of game will be tough and exhausting – but it will also be a genuinely terrifying experience for one lucky player.



A Trail of Cthulhu GMC in Armitage Files format

Name: Frank Warren

Physical Description: late 50s, papery complexion, thinning hair

Sinister: Frank Warren became a pharmacist to make use of the alchemical secrets his father taught him from the family collection of moldering Renaissance manuscripts. He chose to operate in this desperate urban neighborhood because it supplies him with an inexhaustible list of test subjects who will never be missed should something go wrong. In his insane rambles through the New England countryside he has stumbled across various remnants of creatures that should not be. These scraps of flesh he has distilled into an assortment of elixirs. Eventually he hopes to invent a cure for death, without the vulnerabilities of the quack system discovered by that fool, Dr. Muñoz. This noble ambition surely compensates for any number of quasi-indigents slightly hastened to their graves. Should Warren sense that the investigators pose a threat to him, he attempts to dose them with one of his more lethal concoctions.

Innocuous: Warren first set up shop when this was a nice neighborhood, before the rot set in. He notices the terrible things moving in the shadows, but doesn’t say anything. Who would believe him? Frank just wants to get home to his ailing wife Helen, bolt shut all three locks on his apartment door, and stay out of trouble.

Stalwart: Warren learned his profession at Miskatonic University. He could have established a pharmacy in the rich, safe part of town, but instead took over his father’s drug store. Here, people need him. He has only just begun to notice the moving shadows down on Fourteenth Street. Every time the hairs on his neck rise up, he makes a note with a stubby pencil in his notebook. Any day now he may ring up his old friend Armitage at the university to share his observations.

Alternate Names: Bob Du Brey, Sidney Alden, Wilfred Brecher

Alternate Descriptions (1): mid 40s, wavy hair, luxuriant mustache

(2): late 60s, inexplicably resembles Mark Twain

(3): early 60s, rounded glasses, forbidding brow

Defining Quirks: (1) suffers terrible hay fever; (2) hums songs from Astaire-Rogers movies; (3) looks at his fingernails when nervous

Academic and Technical Abilities: Medicine, Pharmacy

General Abilities: Athletics 2, First Aid 8, Fleeing 2, Health 2

Alertness Modifier: 1

Stealth Modifier: –1



Trail of Cthulhu is an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu and its many supplements and adventures in the Pelgrane Shop.

Kenneth Hite and Robin D. Laws talk worldbuilding, creating interesting female pregens for con games and freeforms, Gareth Ryder-Hanrahan and time-traveling health care in a brand new episode of Ken and Robin Talk About Stuff.

A great review of The Armitage Files from Dreams in the Lich House. You can read the full review here.

This product takes the handout concept and turns the dial up to 11 with these spectacular props.

We are very pleased to have been nominated for a second time in the Golden Geek Awards.

Ashen Stars and Bookhounds of London have been nominated for Best Artwork and Presentation, The Armitage Files and Bookhounds of London for Best Supplement.

You can vote here, but you need to be a member with Geek Gold.



A review of The Armitage Files on offering top marks (10/10)

For anyone who doubts an investigative sandbox campaign is possible, this book is the winning counterargument.

I know of no other books like this one. I hope this is not the case for long.

by Robin D. Laws

The Armitage Files, my recent, Silver-Ennie winning, campaign sourcebook for Trail of Cthulhu, has been hailed for an innovative approach—one I will now encourage you to steal.

If you’ve yet to check it out, Armitage presents a new take on the epic Cthulhu campaign. It provides building blocks for a player-driven, GM-improvised grand mystery series. Those elements include people, places, tomes, and organizations. Each of these entries can be attuned to the GM’s immediate needs as they arise in the story. A person might be stalwart or sinister, an organization benevolent or hostile. With some filing off of serial numbers, each can be used multiple times under different circumstances.

Tying these together are the eponymous documents that comprise the heart of the campaign, and the experience. The book arises from the observation that the player handout is the essential currency of a classic Cthulhu gaming experience. Those of us who discovered the story side of roleplaying through exposure to early, iconic Call of Cthulhu products learned to love the handouts that came with each scenario. Our characters risked life and sanity to secure them. As players, we grasped them in our hands and tried to puzzle out their significance. Though printed on humble cardstock, these brown-on-brown documents provided an imaginative portal into the terrible Lovecraftian reality our characters found themselves trapped in.

The Armitage Files also builds on an idea I explored in a Dying Earth supplement, The Kaiin Player’s Guide. It’s a mammoth, super-detailed setting book. By tradition, such products have been aimed at GMs. This book is written for players, assuming their characters are residents of its decadent, white-walled city, who well know its people and pathways. They are encouraged to thumb through it, find the plot hooks they like, and proactively declare what they’re going out to interact with them.

Armitage pulls a similar trick with a series of mysterious documents. They arrive unbidden at Miskatonic University’s secret inquiry into the Mythos. Their damaged, increasingly chaotic pages are in the hand of the project leader, Henry Armitage—but he has no recollection of having written them. They read like fragmentary case files. The investigators decide which of their many details they follow up on. The GM weaves a narrative around their choices.

I always hoped that someone else would steal the concept behind Kaiin. That’s how new ideas get into the collective bloodstream of the form.

We’re cooking up various projects informed by the Armitage approach. [[Ed’s note: The most notable of which is the now-published Dracula Dossier…]]

But, as Pelgrane Press does not yet publish every roleplaying game on the market, here’s how you might borrow it for games beyond the GUMSHOE fold.

Vampire: the WikiLeaks

Hidden between the lines of an apparent spam email, the characters receive a link to a super-secure black site only they can seem to access. Every so often, a new text file appears briefly on the site, ready for download. It contains excerpts from the surveillance files of an unidentified high-level observer of vampiric activity. They might have been composed by a hunter, but seem more like the work of an intelligence agent serving a bloodsucking Prince—the one, coincidentally enough, who seems to be trying to kill them, for reasons they have yet to discover. Can they use its secrets to bring him down before he kills them? Or, in a deadly double game, are they really doing his bidding all along?

Your Favorite High-Level Superhero Game

This fits Champions, Mutants and Masterminds, or any similar game set in a wild and crazy super-world reminiscent of the DC or Marvel universes.

The heroes investigate a series of bizarre incidents in which people with low-level psychic powers go on destructive, spree-level rampages, invariably ending in their deaths. Each of the victims-slash-killers is revealed to have left a record of vivid visions received before they lost their minds completely. The records come in various forms: paintings, audio recordings, video diaries, even a comic book. Similarities of content and imagery show that they have to derive from some common, external force. Eventually the heroes discover that the source is a satellite sent from an alien future to document the event that dooms mankind. Its transport through time damaged it, causing it to beam flashes of its database to vulnerable minds. But this is just a symptom of the real crisis. Can the heroes piece together the contents of the visions and database to identify and stop the impending catastrophe?


If the handout is the basic currency of a Cthulhu game, its fantasy equivalent is the dungeon map. This one warps Armitage’s player-driven plotting to its most unfettered extreme of hack and slashery, in an approach that might be called “dial a fight.”

Deep in a supposedly impregnable underground complex, the adventurers discover an ancient artifact. On the twenty equal sides of this polyhedral device appear engravings of fearsome creatures, guarding fabulous treasures. When a character places his palm across one of the twenty surfaces, she and her comrades are transported across space and time to a place of battle. There they find the pictured monster, which they must defeat to seize the treasure. Once there, they discover that they took a one-way trip. To return home to their lives—and the treasuries they’ve filled during their long careers—they must find a side that corresponds to their home time and place.

When a face is used, a new one takes its place. As they pop willy-nilly through history and other dimensions, they eventually discover that one of the faces leads to the end of the world. Will they get home before you decide to pack up the campaign, er, before they accidentally destroy reality?

Unless you’re a master of instant prep with your favored D&D edition, you’ll likely want to have the players pick their next couple of monsters and treasures at the end of each session.

Thanks to Steve Moss for asking to hear more about The Armitage Files.


The Armitage Files is a supplement for Trail of Cthulhu, an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu and its many supplements and adventures, in print and PDF at the Pelgrane Shop.

Paco Garcia Jaen at G*M*S Magazine has posted an excellent review of The Armitage Files.

This is a masterpiece. Not because the adventure is astonishingly good and attractive, but because the thinking behind the book, the perfect sandbox layout and the second to none writing is as good as it gets. This is Robin D. Laws at his best.

You can read the full review here.

John Stavropoulos declared Armitage Files his Best RPG Purchase of 2010. Read more here.

Why do I love it? Most modules don’t fit my style of GMing. I’m a very improvisational GM who likes to build scenarios around my players (rather than run railroady static scenarios where the players feel disconnected and “dropped in”). The Armitage Files works perfectly with how I run games.

Another offering from Lowell Francis at RPGGeek, his review of Armitage Files is simply entitled ‘wow’ and you can read the whole thing here.

The Armitage Files is a unique game book. Pelgrane’s once again demonstrated that they’re willing to go in new and novel directions. At the same time we once again get their high standards of production, layout and illustration. I know I’ve spent a lot of attention on the Gumshoe line, but they keep making interesting things… Quite honestly I wish I’d never read this sourcebook. Instead I wish I’d been able to come into a campaign using this without any foreknowledge. That would have been the coolest thing… This product blew my mind. I think every GM with an interest in alternate campaign approaches ought to read it.

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