# Trail of Cthulhu *Created:* 2026-09-13, *Modified:* 2026-10-19 ![[Trail of Cthulhu (cover).jpg|600]] **Trail of Cthulhu** is Kenneth Hite's answer to the one reliable way a mystery dies at the table: somebody rolls badly, misses the one clue that matters, and the whole adventure grinds to a halt while everyone stares at the Keeper like it's somehow his fault. It runs on the **[[Gumshoe|GUMSHOE]]** engine, and its founding promise is the thing that made it a landmark — get yourself to the right place with the right ability and you *will* find the clue. No roll. No drama about the finding. What's left to be afraid of is everything after the clue: what it costs to follow the trail, what it does to you, and how much of yourself is gone by the time the pattern snaps shut. Set in the grim 1930s Mythos, it splits its heart two ways — **Purist** for the philosophical doom that made **[[Call of Cthulhu]]** the classic it is, **Pulp** for two-fisted running and gunning — and it's still the genre's best argument that horror is served better by a ledger you watch dwindle than by a dice pool that can just shrug. ## Setting Investigators are ordinary folks with an ordinary past — doctoring, journalism, hoboing — the **Occupation** that explains the skills they carry, before they stumbled onto the truth the world is built to hide. Alien gods and monsters fell to Earth in prehistory, warred over it, and now sleep beneath the everyday; and there are those who want to wake them. You're among the few who suspect, and from that moment your life's work is keeping the doors to the Outside shut, no matter the cost in life or sanity. The book doesn't flatter you about it: you'll piece together clues from books bound in human skin and walls built before humanity, you'll go wherever the answers are, and you'll do what needs to be done. Investigative scenarios, it insists, aren't about finding the clues — they're about interpreting the ones you do find. The tonal engine is the **Purist / Pulp** dial. **Purist** takes its model from Lovecraft's later, starker work (*The Colour Out of Space*, *At the Mountains of Madness*) — philosophical horror where uncovering the truth dooms seeker and bystander alike and lost Sanity never returns. **Pulp** reaches for the desperate action of Robert E. Howard's Mythos stories — the physical struggle, survival weighed a little more toward the heroes. It's a dial, not a wall; a Keeper can lock one end out entirely or let a campaign drift between them. The book even carries guidelines for adapting Chaosium's immense **Call of Cthulhu** scenario catalog, which is the hobby's quiet way of admitting this thing was built to be lived in. ## Mechanics ### The Core Loop Trail runs on Robin D. Laws's **GUMSHOE**, whose founding hunch is that a mystery shouldn't be able to die of a bad die roll. So **Investigative abilities** — Academic, Interpersonal, and Technical: Accounting, Cop Talk, Evidence Collection, Library Use, Languages — simply *work*. Get to the right scene, say the word, and the clue is yours, no roll and no fumble. The drama isn't in *finding* the thing but in what you do with it: a **spend** of 1–2 pool points buys the *extra* — the favour repaid, the hidden door, the detail that makes you look like you know what you're doing. It's the bargain that runs the whole engine: the facts are free, and the consequences are what you pay for. **General abilities** are for outcomes that genuinely hang in the balance, and the resolution is a single clean die roll. The Keeper sets a **Difficulty Number** from 2 to 8 (4 is the default). You roll one d6, and *before* it falls you may commit any number of points from the ability's pool — each point adds +1 to your result, so you're betting against a number you already know. Meet or beat the Difficulty and you succeed; the points you bet are gone either way. Blow it and you've shot your bolt: a retry needs a genuinely new approach and must spend *more* than the last attempt. In **Purist** play the Keeper never tells you the Difficulty, because the book clearly enjoys the flinch; **Pulp** Keepers may reveal it, except **Sense Trouble**, which stays secret in both. When the group works together, one character leads the test while everyone else chips in a pool point — and every ally who can't pay raises the Difficulty instead. Your pools are rations, not rivers — they refresh between scenarios, which is what makes Trail as much a game of husbanding spend as of rolling, and keeps every clue you find feeling paid for. ### Character Creation Chargen starts with an **Occupation** from a gloriously period list — Alienist, Antiquarian, Archaeologist, Artist, Author, Clergy, Criminal, Dilettante, Doctor, Hobo, Journalist, Military, Nurse, Parapsychologist, Pilot, Police Detective, Private Investigator, Professor, Scientist — and the quiet question of whether you still hold the job or have torched your old life to chase the Mythos. Occupations make you competent cheaply: **Occupational abilities** at half-price, a **Credit Rating** band (genteel shorthand for starting wealth), and usually a special rule. Then a **Drive** — Curiosity, Duty, Revenge, Scholarship, Thirst for Knowledge, Sudden Shock — there to get you down into the sub-basement no sane person would consent to enter. Points are tight. Investigative build points scale with the table (16 for four or more players, 18 for three, 24 for two), General abilities get a flat 65, and Sanity 4, Stability 1, and Health 1 come free. Two optional structures give the build its soul: **Pillars of Sanity** — one abstract thing you trust implicitly, faith or family or the value of science, per three points of Sanity — and **Sources of Stability**, one named person who keeps you sane per three points of Stability. The bill comes due for knowing too much: with any **Cthulhu Mythos** rating at all, your Sanity can never exceed 10 minus it. ### Stability, Sanity, and Madness This is where the game earns its keep — two meters for two kinds of damage. **Stability** is the short-term one, "how close you are to snapping today." It gets whittled down mid-adventure by gunfights, gore, and the merely awful, and fully refreshes between scenarios — though in **Purist** play it's hard-capped at 12, which tells you how the book feels about your chances. When an incident challenges your grip, the Keeper calls a **Stability test** against Difficulty 4, and Mythos shocks always add at least +1. You may spend Stability to bolster the roll like any General ability, but here's the bite: fail, and you lose the full potential loss *on top of* whatever you spent bracing yourself. Above 0 your Stability has no mechanical effect at all — losing it is pure roleplay, the twitches and the babbling — until it goes negative, and then the Mythos starts eating your Sanity. **Sanity** is the long con — "how close you are to seeing the Truth forever." You never roll it and never spend it; the Mythos simply leaches it away, whether through a **Mythos shock** (Stability driven to 0 or −5 costs 1 Sanity; −6 to −11, 2) or by using your **Cthulhu Mythos** ability to piece the horror together. At 0 your beliefs are gone and the character shuffles off to an asylum — or, worse, becomes a willing servitor of the Great Old Ones. Shatter a **Pillar of Sanity** and it costs extra; reach the Purist endgame, the **big reveal** that proves your Drive meaningless, and you take 8 Stability (or triple the shock) with any Sanity loss doubled. In Purist games that Sanity never comes back — a game that remembers losing your mind is the whole point, and it is not sorry about it. **Sources of Stability** turn your support network into a hostage situation. The people and comforts that keep you sane can be turned, possessed, or simply hurt by the entities you've angered — and losing them costs Stability now and permanently burns the rating points they were tied to. You wanted to be the hero? Fine. They know where your mother lives. ### Drives The **Drive** is the game's insurance against sensible play. Obey it and you get Stability back — 2 points for a **hard driver** (the Keeper yanking your chain into trouble), 1 for a **soft one** — capped at your rating. Refuse, and the bill is automatic with no roll to dodge it: 4 points or a third of your pool to fight a hard driver, 2 for a soft one. It's a tidy way to make the genre's mandatory bad decision feel like a compulsion rather than a mistake — you're not being stupid, you're being *driven*. ### Tests and Contests For most General ability use the Keeper should just let it happen; tests are for the moments that matter or the genuinely hard. A simple **test** is the one-d6 affair from the Core Loop — spend pool points for +1 each, beat the Difficulty (2–8, default 4). A **contest** is where two characters actively try to thwart each other, and it's the model for a **chase**, where you bolt and the thing at your back gives chase. Contestants take turns testing the contested ability, usually against Difficulty 4, and **the first to fail loses — no winner's roll required**. The Keeper sets the order: in a chase the one who fled goes first, and when it looks simultaneous the lower rating acts first. Learning to run, it turns out, is not a failure of nerve — the book treats it as a skill you're allowed to spend on. ### Combat Fights are contests with one important twist: you don't lose when you fail a roll, you lose when you're seriously wounded or knocked out. Combat runs on the pairings **Scuffling vs Scuffling**, **Scuffling vs Weapons**, or **Weapons vs Weapons** for close quarters, and **Firearms vs Firearms** when you're apart with guns. The **aggressor** — whoever moves first — usually presses the advantage, and when that's unclear the combatant with the higher current pool in the fight ability chooses whether to strike or defend. To hurt someone you roll against their **Hit Threshold** — your defensive Difficulty, 3 by default or 4 if your Athletics is 8+. Match or beat it and you deal damage: another d6 modified by your weapon (fists or a kick −2; a knife, blackjack, or nightstick −1; a machete, heavy club, or light firearm 0; a sword or heavy firearm +1 — and a firearm adds an extra +2 at point-blank), scraped off the target's **Health**. Health runs below zero, and dropping below zero drags out a **Consciousness roll** — a test against the absolute value of your pool, which you can push through by burning extra Health for +1 per point. At 0 to −5 you're **hurt**: no Investigative spends, and every Difficulty — including an opponent's Hit Threshold — climbs by 1. At −6 to −11 you're **seriously wounded** and out of the fight. At −12 you're **dead**. Armor is a tin hat or a leather duster — not a power fantasy, a plea. The game's closing argument is that running away, far from cowardly, is the genre-correct move, and the mechanics quietly reward the people who make it. ## Editions - **Trail of Cthulhu** (2008) — Kenneth Hite's original hardcover, published "by arrangement with Chaosium" and over twice the length of the earlier GUMSHOE games; it established the Purist/Pulp modes and the sanity triad. - **Trail of Cthulhu Player's Guide** — the core rules with the Mythos secrets and setting excised, a clean player-facing cut of the 2008 book. *In the library.* - **Trail of Cthulhu Second Edition** (2026) — Hite collaborating with Gareth Ryder-Hanrahan; a full-color corebook fully compatible with the first edition's supplement line, twenty Occupations, over a dozen Drives, three campaign frames (the Miskatonic-flavored **Armitage Inquiry**, the small-town **Beneath Unknown Skies**, and the Chicago-set **Shadows Under Chicago**), plus two decades of accumulated GUMSHOE guidance folded in. ## Supplements A long and celebrated line of campaigns and settings runs under the core, and the Second Edition keeps the whole run compatible: - **Eternal Lies** — Gareth Ryder-Hanrahan's sprawling, globe-spanning campaign epic, widely regarded as one of the great investigative-horror arcs. - **The Armitage Files** — Kenneth Hite's improvisational campaign frame built around Miskatonic University's archives, where the Investigators assemble the file themselves. - **Bookhounds of London** — the campaign where the Investigators are rare-book dealers sliding into the Mythos commerce of the antiquarian trade. - **Dreamhounds of Paris** — the surrealist-artist setting, where Parisian dreamers steer the collective unconscious against the Mythos. - **Cthulhu City** — an alternative urban campaign setting, a corrupted metropolis ordered around its own monstrous custodians. - **Stunning Eldritch Tales** — Robin D. Laws's anthology of four scenarios, most leaning Pulp. - **Shadows Over Filmland** — Kenneth Hite and Robin D. Laws's *Backlot Gothic* setting and twelve scenarios, dragging the Mythos into the shadowy studio lots of Hollywood. - **Arkham Detective Tales** — Gareth Ryder-Hanrahan's four scenarios and a campaign frame built around the Arkham detective beat. - **Rough Magicks** — Kenneth Hite's expanded treatment of magic in Trail: new setting material and rules for the tomes and spells that run the Mythos. - **Cthulhu Apocalypse** — Graham Walmsley's post-apocalyptic series, rules and scenarios for when the Mythos finally wins and the End Times begin. - **The Keeper's Screen** with the Keeper's Resource Book — Simon Carryer's rules summary and expanded abilities and occupations for the keeper behind the screen. ## Related products - **Cthulhu Confidential** — the GUMSHOE **One-2-One** variant, a one-player, one-Keeper adaptation that strips the engine down to a single Investigator. ## References - [Trail of Cthulhu — Wikipedia](https://en.wikipedia.org/wiki/Trail_of_Cthulhu_(role-playing_game)) - [Trail of Cthulhu — Pelgrane Press](https://pelgranepress.com/product-category/gumshoe/trail-of-cthulhu/) - [Trail of Cthulhu Second Edition — Pelgrane Press](https://pelgranepress.com/trail-of-cthulhu-second-edition/) - [In-Depth RPG Review: Trail of Cthulhu — Wired](https://www.wired.com/2011/11/in-depth-rpg-review-trail-of-cthulhu/) - [RPG Review: Trail of Cthulhu — Shut Up & Sit Down](https://www.shutupandsitdown.com/rpg-review-trail-of-cthulhu/) - [Trail of Cthulhu – System Cheat Sheet — The Alexandrian](https://thealexandrian.net/wordpress/35587/roleplaying-games/trail-of-cthulhu-cheat-sheet) - [GUMSHOE System — Wikipedia](https://en.wikipedia.org/wiki/Gumshoe_System)