The Pandemonium Engine — Overview
Named for Valente’s city that rearranges itself according to the needs of narrative, the Pandemonium Engine is a generation system for West Marches campaigns. It collapses a six-layer graph into a complete, coherent settlement around the specific party and quest that triggered generation — then updates gracefully as players observe and change the world.
The core loop: Seed → Collapse → Observe → Pin → Regenerate → Repeat.
The Design Philosophy
The engine starts with a problem in responsive generation and solves it by treating settlement generation as Wave Function Collapse — the same algorithm that powers procedural level generation, and the same operation that collaborative worldbuilding games have always been doing by hand.
The architecture is The Six-Layer Graph — a die with six faces (People, Factions, Settlement, Geography, Quests, Lore), each face a graph, connected by posts that tunnel through the die. History isn’t a layer; it’s the meaning encoded on every edge.
How Generation Works
Sessions are seeded by a focal player and focal quest. These collapse first; everything else propagates from them. Party composition varies, so different parties produce different realizations of the same constraint graph — same bones, different paths.
The engine produces two outputs: the Western Horizon (what players have observed, pinned, immutable) and the Shadow Horizon (the complete collapsed state, provisional until observed).
When players say “I know a guy”, they’re pinning a node. The GM’s role shifts from gatekeeper to constraint referee — if it hasn’t been observed, it can be true.
When pins contradict the Shadow Horizon, Regeneration handles it gracefully. Settlements solidify over time as more nodes are pinned by play.
Two structural guarantees underpin every collapse: the GUMSHOE Guarantee (a lead must exist for every relevant party capability) and the structural dissenter rule (every faction contains at least one dissenter).
The Spectrum
The engine runs at any point from full artisanal to full automatic. Collaborative games pin tiles manually. The algorithm collapses everything else. The output is structurally identical regardless of mode.
The Six Layers
Each layer has its own folder with node types, edge types, and adjacency rules:
| Folder | Layer | Opposite Face |
|---|---|---|
| 01 - People | NPCs, PCs, guild members | Factions |
| 02 - Factions | Power structures, allegiances | People |
| 03 - Settlements | Buildings, landmarks, districts | Geography |
| 04 - Geography | Hexes, terrain, routes | Settlements |
| 05 - Quests | Hooks, leads, McGuffin fragments | Lore |
| 06 - Lore | Rumors, secrets, legends | Quests |
Connection to The Western Horizon
The engine is the connective tissue between the collaborative tools. Chronicle, Beak, Feather & Bone, Street Magic, Claw Atlas — they all pin tiles. The engine collapses everything else into coherent existence around them.
See also: Stories as Hyperedges — how narrative binds multiple nodes into irreducible units and creates gravitational centers in the graph.