Any system
Designed to work with Call of Cthulhu, Delta Green, Trail of Cthulhu, Cthulhu Dark, and any other Lovecraftian or horror RPG.
The Eldritch Engine
Roll. Connect. Conjure cosmic dread. A complete Lovecraftian adventure generator that works with any horror RPG — in minutes.
Three main tables. Nine subtables. Dozens of interconnected results that combine into fully-formed scenarios, complete NPCs, locations, artifacts, monsters, clues, threats, twists, and outcomes — all tuned for creeping dread and fragile sanity. Three worked sample scenarios show you exactly how it all fits together.
Whether you run Call of Cthulhu, Delta Green, Trail of Cthulhu, Cthulhu Dark, or any other horror system, The Eldritch Engine adapts to your table, your era, and your tone.
Any era
Era-specific adaptations for Classic 1920s, Gaslight Victorian, Modern Day, and Pulp Action — each with tailored tone guidance.
Three complete scenarios
Fully worked examples — The Missing Fisherman, The Whispering Shadows, and The Crawling Legacy — show exactly how table rolls become playable adventures.
Endless variety
Dozens of options per table ensure no two sessions unfold the same way. Random Events and Complications tables keep every session unpredictable.
Roll a handful of dice. In minutes you have a scenario blueprint, a mystery origin, a revealed horror, key NPCs, a location, a monster, an artifact, clues, threats, a twist, and an outcome. The Eldritch Engine does the scaffolding so you can focus on the dread.
How it works
The Engine runs on three main tables rolled first — Scenario Blueprint (1d10), Mystery Origin (1d10), and Revealed Horror (1d10) — which set the overall shape of the story. From there, you consult whichever subtables fit your results: People, Locations, Monsters, Artifacts, Clues, Threats, Twists, Outcomes, and Themes. Not every subtable is required for every scenario — you pick what enhances the story you’re building.
Every result is a prompt, not a prescription. A Corrupt Official doesn’t have to be the sheriff — that’s just where the dice pointed you. The three worked sample scenarios in the book demonstrate this process in full, showing how a set of rolls becomes a written-up adventure with NPCs, scene flow, atmosphere notes, and a Keeper reference sheet ready to run.
The tables at a glance
The Core Three
Scenario Blueprint sets the structure: classic investigation, race against time, haunted location, artifact unleashed, dreams and madness, and seven more. Mystery Origin provides the inciting incident. Revealed Horror names what’s really going on.
NPCs and Locations
12 NPC archetypes from obsessive antiquarians and secretive cultists to haunted survivors and retired detectives. 12 locations from fog-shrouded harbors and crumbling chapels to university libraries and deserted factories.
Things in the Dark
12 Mythos monsters with descriptions: Deep Ones, Byakhee, Shoggoths, Mi-Go, Hunting Horrors, Hounds of Tindalos, and more. 12 immediate threats from cultist ambushes and supernatural curses to betrayal from within.
Evidence and Objects
12 artifacts including the Black Stone, Elder Sign Amulet, Mirror of Leng, Silver Key, Shining Trapezohedron, and The Clockwork Heart. 20 clue types from bloodstained letters and medical reports to witnesses with amnesia.
Where It Goes
20 plot twists including false memories, time loops, the dead returning, and the investigators realizing they caused the very events they tried to stop. 20 outcomes from pyrrhic victory to world-altering cosmic failure.
Any Time Period
Adaptation tips for Classic 1920s (scholarly research, gentleman investigators), Gaslight (Victorian science vs. superstition), Modern Day (technology and social media), and Pulp Action (heroic outcomes, more combat).
Three worked scenarios
The Missing Fisherman
A disappeared fisherman in a remote coastal village. A corrupt sheriff working with an ancient Deep One cult. A waterproof camera full of underwater ritual photographs. And a cycle of murder and paranoia that will begin again whether the investigators succeed or not.
The Whispering Shadows
A whole town sharing the same nightmare. A deserted factory where corridors loop and hours vanish. A Whispering Locket that fractures memories and links listeners to the Dark Young of Shub-Niggurath. Reality never fully recovers, even if the cultist is unmasked.
The Crawling Legacy
An unexplained death at a long-abandoned factory tied to a suppressed government experiment. A desperate sister who knows something was moving in the shadows. A Crawling Medallion that won’t stay still. And a secret organization watching to see how the investigators handle what comes next.
Inside the book
The Generator
- 3 main tables: Scenario Blueprint, Mystery Origin, Revealed Horror
- 9 subtables: People, Locations, Monsters, Artifacts, Clues, Threats, Twists, Outcomes, Themes
- Random Events and Complications tables
- Full usage guide with step-by-step instructions
Sample Scenarios
- Three complete worked adventures
- Each with full scenario write-up and Keeper reference sheet
- Scene flow cues, atmosphere tips, and NPC notes included
- Shows exactly how rolls translate into playable games
Keeper Tools
- Quick Reference Card for in-game use
- Blank Keeper scenario template for your own creations
- Full appendix for seamless table-side access
- Era-specific adaptation guidance for four time periods
Compatibility
- System-neutral — no stat blocks, no system-specific rules
- Works with Call of Cthulhu, Delta Green, Trail of Cthulhu, Cthulhu Dark, and more
- Tone guidance for horror, investigation, action-adventure, and psychological play
- Free online generator at games.akapplegarth.us
Who this is for
- Keepers and GMs who want a reliable prep tool that sparks genuine inspiration rather than generic results.
- Anyone who runs multiple horror systems and needs a single toolkit that adapts to all of them.
- Improvisational Keepers who want structured randomness they can riff off at the table.
- Campaign builders who need a fast way to generate one-shot seeds, side adventures, or recurring antagonist hooks.
Note: The Eldritch Engine is a Keeper and GM toolkit, not a standalone scenario. It generates the framework for Lovecraftian adventures — rules and stat blocks come from your game of choice.
Generate a Lovecraftian scenario in seconds — no account needed.
Your next horror session is one set of dice rolls away.
The Eldritch Engine gives you a complete system-neutral Lovecraftian adventure generator — interconnected tables, era adaptations, three worked scenarios, and every Keeper tool you need to conjure cosmic dread at any table.