About

Tabletop RPG game masters face a recurring problem: preparation time. A single session of Things From The Loop or Things From The Flood demands a coherent mystery built from interconnected elements - a strange phenomenon, a location charged with Cold War paranoia, child protagonists navigating adult secrecy, and a technological threat rooted in the Loop's particle accelerator. Get the tone wrong and the session collapses into generic horror. This generator produces structured scenarios by cross-referencing thematic databases of 200+ narrative elements, weighting selections so that threat types influence location choices, which in turn shape NPC motivations. The output is not random noise - it is a narratively coherent scaffold.

The tool covers both the 1980s setting (Things From The Loop) and the 1990s setting (Things From The Flood). Note: generated scenarios are starting points. The system assumes a Scandinavian or American Loop setting and does not account for fully custom homebrew worlds. Pro tip: generate 3 - 4 scenarios and cherry-pick elements across them for maximum originality.

Formulas

Scenario generation uses weighted random selection with thematic cross-referencing. Each element category has a base probability pool, modified by prior selections to ensure narrative coherence.

P_adjusted = P_base × W_theme × W_era

Where P_base is the uniform probability of selecting any element from its pool, W_theme is a weight multiplier (0.5 - 2.0) based on thematic affinity with previously selected elements, and W_era is a binary filter (0 or 1) excluding elements from the wrong era setting.

For reproducible generation, an optional seed value feeds a Linear Congruential Generator:

X_n+1 = (a × X_n + c) mod m

Where a = 1664525, c = 1013904223, m = 2³². The normalized output X_nm replaces Math.random() calls, producing identical scenarios for identical seeds.

Reference Data

Element	Category	Era	Description
The Loop	Location	Both	Underground particle accelerator. Source of all anomalies.
Cooling Towers	Location	Both	Massive concrete structures. Emit low hum at night.
Gravitron	Threat	Loop (80s)	Gravity manipulation device malfunctioning in a barn.
Echo Sphere	Threat	Loop (80s)	Metallic orb replaying conversations from the past.
Flood Machine	Threat	Flood (90s)	Device leaking temporal fluid, aging objects rapidly.
Dr. Elsa Borg	NPC	Both	Riksenergi scientist. Knows more than she reveals.
The Janitor	NPC	Both	Loop maintenance worker. Has seen things underground.
Magnetrine Vessel	Object	Both	Hovering cargo ship. Sometimes found abandoned in fields.
Robots (Wandering)	Threat	Both	Autonomous machines from decommissioned programs.
Time Distortion	Phenomenon	Flood (90s)	Localized time loops. People repeat actions unknowingly.
The Mist	Phenomenon	Both	Unnatural fog emanating from exhaust vents.
School Gymnasium	Location	Both	Where kids gather. Rumors spread here first.
Junkyard	Location	Both	Abandoned tech graveyard. Scrap robots and parts.
The Lake	Location	Both	Deep, cold. Strange lights visible beneath the surface.
Government Agent	NPC	Flood (90s)	Investigating the Loop shutdown. Distrusts children.
Parallel Dimension Leak	Phenomenon	Flood (90s)	Objects or people from alternate realities appear.
Missing Child	Hook	Both	A classmate vanishes. Last seen near the cooling towers.
Strange Drawings	Hook	Loop (80s)	A kid's crayon art predicts future events accurately.
Power Outage	Hook	Both	Town-wide blackout. Only Loop facilities stay lit.
The Bully	NPC	Both	Older kid who saw something and is now terrified.
Abandoned Lab	Location	Flood (90s)	Post-shutdown research site. Equipment still hums.
Dinosaur Sighting	Hook	Loop (80s)	Temporal displacement brings prehistoric life to the present.
Body Swap	Phenomenon	Flood (90s)	Two people exchange consciousness. One may be a robot.
The Teacher	NPC	Both	Physics teacher. Former Loop intern. Guilt-ridden.
Radio Interference	Hook	Both	Walkie-talkies pick up voices from decades ago.

Frequently Asked Questions

Each element in the database carries tag metadata (e.g., "technological", "supernatural", "melancholy", 'paranoia'). When the generator selects a threat tagged "technological", subsequent location and NPC selections receive a multiplier boost for matching tags. A "technological" threat is more likely to pair with "Abandoned Lab" than "The Lake". The weight multiplier ranges from 0.5 (thematic clash) to 2.0 (strong affinity), creating narratively consistent combinations without being fully deterministic.

Things From The Loop is set in the 1980s when the Loop particle accelerator is operational. Threats tend to be wonder-driven: robots, gravity anomalies, time echoes. The tone is nostalgic. Things From The Flood is set in the 1990s after the Loop has been shut down. Threats are darker: body horror, identity loss, decaying technology, corporate cover-ups. The era filter ensures elements match the selected time period. Selecting "Both" includes the full pool.

Yes. Enter a numeric seed value before generating. The generator uses a Linear Congruential Generator (LCG) seeded with your value, producing deterministic pseudo-random sequences. Share the seed number and era setting - any user entering the same values will get the identical scenario. Leave the seed field empty for true random generation via Math.random().

The generator selects across 8 independent categories (Hook, Threat, Location, NPC Primary, NPC Secondary, Mood, Complication, Resolution Clue), each with 15-25 options per era. For the "Both" era pool, this yields approximately 25^8 ≈ 152 billion unique combinations. Thematic weighting reduces effective diversity somewhat, but practical exhaustion is impossible.

No. The output is a structured scaffold - a narrative skeleton. It provides the mystery hook, the threat source, key locations, NPCs with motivations, atmospheric mood, a mid-session complication, and a resolution clue. The game master must flesh out scene transitions, dialogue, and pacing. Think of it as a creative brief, not a script. Generating 3-4 scenarios and combining favorite elements across them produces the strongest results.

The element database assumes either the Swedish Mälaren Islands or the American Boulder City Loop setting, which are the two canonical locations. Location names like "The Lake" or "Junkyard" are generic enough to transpose. However, culturally specific NPCs (e.g., 'Riksenergi Scientist') may need renaming for non-Scandinavian campaigns. The tool does not support adding custom elements to the database.