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Mneme World Generator/Revision Notes 260222

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Mneme World Generator – Revision Notes & Upcoming Changes (260222)

Source page
Mneme_World_Generator_260222
Date
22 February 2026
Status
Draft — changes to be incorporated into the next version
Version
Draft 2.1 (Added Mutual Hill Radius Logic)
Philosophy
Simulationist, Recursive, Modular

This page captures the design notes and structural changes from the 260222 revision document. These are the changes and new mechanics to be incorporated into the main Mneme World Generator rulebook.

Proposed New Structure

The revised document proposes reorganising the rulebook into the following top-level chapters:

  1. Introduction — Credits, Key Definitions, Core Philosophy, Required Tools
  2. Level 1: Stellar Generation — System Budget, Primary Star, Multiple Stars, Barycenters, Rule of Five
  3. Level 2: Inras (IntraStellar) Systems — Generation Pool, Gravitational Waterfall, Mutual Hill Radius, Orbital Zones
  4. The Prime Inras (Main World) — Main World Type, Habitability Waterfall Algorithm
  5. Civilisation & World Development — HDI, Gini Coefficient, SOC, Effective Standard of Living
  6. Technology & Hard Sci-Fi Mechanics — Mneme Tech Level System, Tech Distribution, Delta-V Map
  7. Economics & Infrastructure — Credit Recalibration, Starport Generation, PVS
  8. Environments & Equipment — Environmental Systems, Artificial Habitats, Procedural Vacc Suits
  9. Appendices — Traveller/CE Integration, PWA, D66×D6 Tables, Glossary, OGL

Core Design Philosophy (Confirmed)

The foundational approach employs a strictly defined hierarchy of physical and political objects enabling recursive code logic.

"A moon orbiting a planet uses the same physics engine class as a planet orbiting a star."

The four levels of orbital hierarchy are:

Level Name Definition Components
1 Stellar & Barycenters Primary gravity well of the system Stars, Companion Stars, Barycenters
2 Inras (IntraStellar) Systems Major orbitals orbiting the Level 1 anchor Gas Giants, Terrestrials, Dwarf Planets, Asteroid Belts, Circumstellar Disks
3 Sub-Systems Dependent orbitals around a Level 2 body Moons, Ring Systems, Co-orbitals (Trojans/Greeks), Lagrange Point Clusters
4 Details & Surface Specific localities on or within a Level 2/3 body Continents, Biomes, Craters, O'Neill Cylinders, Surface Centrifuges ("Magicians")

New Mechanics to Be Added

Stellar Generation

Companion Star Cap Multiplier (New)

To ensure a companion star is never more massive or luminous than the primary, a cap multiplier is applied:

  1. Convert Primary's Class/Grade to a linear value (0–100 scale)
  2. Calculate: Cap Multiplier = Primary Value / Max Possible Value
  3. Roll for Companion normally, then multiply result by Cap Multiplier
  • Outcome: Mathematically guarantees Companion ≤ Primary without complex lookup tables

Multi-Star Hierarchy Roll (New)

For systems with 3+ stars, determine hierarchy with a D6:

D6 Roll Result
1–3 New star orbits the Primary (P-Type / Circumbinary)
4–6 New star orbits the Previous Companion (S-Type / Hierarchical)

The Rule of Five — Formalised Forbidden Zones

Limit Formula
Inner Forbidden Zone Distance / 5
Outer Forbidden Zone Distance × 5

No stable planetary orbits can exist between these two values.

Orbital Zone Formulae (New — Replaces Zone Table)

Snow Line

D_snow = 2.7 × √L_Star

Habitable Zone

HZ_center = √L_Star
HZ_inner  = 0.95 × HZ_center
HZ_outer  = 1.37 × HZ_center

Zone Map

Zone Range Description
Infernal Zone 0.0 to 0.1 AU Hot Jupiters
Inner Zone 0.1 AU to HZ_inner Too hot for liquid water
Habitable Zone HZ_inner to HZ_outer Goldilocks zone
Outer Zone HZ_outer to D_snow Asteroid Belt usually forms here
Frozen Zone (Giants) D_snow to 100 AU Gas/Ice Giant territory
Scatter Disk > 100 AU Kuiper Belt, Oort Cloud

Mutual Hill Radius — New Core Formula

The Mutual Hill Radius defines the gravitational reach of two planets relative to their star and determines minimum safe orbital spacing. 

R_H = ((a₁ + a₂) / 2) × ∛((m₁ + m₂) / (3 × M_Star))
Variable Definition
a Semi-Major Axis in AU (average orbital distance)
m Planet Mass in Earth Masses or kg (consistent units)
M_Star Star Mass (the dominator — massive stars compress Hill Radii)

The Mneme Stability Standard (K Values)

K Value Meaning
K < 3.5 Chaos Limit (Unstable)
K < 5 Mneme Forbidden Zone (the "Rule of Five")
K ≈ 8 Relaxed System (Sol-like, Jupiter–Saturn baseline)

Gravitational Queue / Waterfall Placement (New)

Replaces the current position table with a physics-based placement algorithm:

  1. Sort all generated objects by Mass (highest to lowest)
  2. Place the heaviest object first (Gas Giant at Snow Line)
  3. Calculate its Forbidden Zone using the Mutual Hill Radius
  4. Place next object — must be at distance Δa > 5 × R_H
  5. If conflict: trigger The Shove — push outer planet to safe distance: a_outer_new = a_new + (5 × R_H) + Variance
  6. Repeat Ripple Effect down the chain until no conflicts remain
  • Far Outer Exception: Objects in the Scatter Disk (>100 AU) are never moved; intruder is ejected instead

Habitability Waterfall Algorithm (Replaces Habitability Table)

Step Factor Logic
1 Mass & Gravity Low mass → Disadvantage on Atmosphere roll. High mass → Advantage
2 Orbital Position (Zone) Inner Zone → Adv on Temperature, Disadv on Biochem. Outer Zone → reverse
3 Composition (Biochem/Volatiles) No volatiles → caps Atmosphere. Abundant volatiles → Atmosphere gains Dense modifiers
4 Hazards (Filter) High hazards can disqualify from "Garden" class immediately
5 Atmosphere Derived from Mass + Volatiles. Acts as temperature multiplier (Greenhouse Effect)
6 Temperature (Final State) Position (Step 2) modified by Atmosphere (Step 5) → Final Habitability Rating

Updated Civilisation Mechanics

Human Development Index (HDI) Roll

  • Mechanic: Roll 2D6 (PDF p.27) → determines HDI (Underdeveloped to Very Developed) and World Average SOC

Gini Coefficient (New)

  • Roll: Determines Inequality Rating (Low to Extreme)

The Elite Ratio Formula (New)

Elite Ratio = (1 / (Gini Score + 1)) × 10%

Effective Standard of Living (New)

Effective SOC = Individual SOC + (World Average SOC - 7)

Tech Divide Access Logic (New)

SOC Level Access
High SOC (Elites) Full access to Setting TL
Mid SOC (Citizens) Access to Standard TL
Low SOC (Subsistence) Restricted to Scavenged / Archaic Tech

Updated Starport Generation

PVS (Port Value Score) is now a calculated metric rather than a table roll: 

PVS = (Habitability / 4) + (TL - 7) + Wealth Modifiers

Social Standing — Doubling Power Scale (New)

SOC is retooled to reflect power-law distributions using a Base-2 logarithmic scale:

  • Every +1 SOC = 2× increase in Income (MC), Wealth, and Resource Access
SOC Meaning
10–11 "Billionaire" / Head of State
14+ Stellar Elite (owns Habitats / Megacorps)

Technology as GDP Multiplier (New Concept)

A SOC 3 person on a TL 15 world may have a higher material standard of living than a SOC 12 person on a TL 3 world.

Planned Supplemental Materials

Procedural Vacc Suit Blender File

  • Justin and Nicco to create a Blender file using Procedural Geometry Nodes
  • Allows random, procedurally generated Vacc Suit designs based on Tech Level and Type
  • Visuals for the Vacc Suit Table to be updated with art and examples

Mneme World Generator PWA

Goals for the PWA (see also Mneme World Generator/PWA (Dec 2025) and Mneme World Generator/PWA Challenges):

  • Offline-capable PWA for multiple platforms
  • Visual, sustainable interface for nested, sortable stellar data
  • Procedural generation algorithms for star systems
  • Data Export/Import via CSV/JSON
  • Local Storage (IndexedDB) for persistent, backend-free sessions
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