---
name: geography-ecology
description: >
  Physical world design — terrain, climate, biomes, resource distribution, and how geography
  shapes civilization. Reference when placing civilizations, designing trade routes, determining
  natural barriers, or building any aspect of the world that derives from the physical landscape.
  The land shapes the people before the people shape the land.
metadata:
  author: nirav
  version: "1.0"
compatibility: Designed for Claude Code
---

# Geography & Ecology — The Land Beneath

Every civilization is a response to the ground it stands on. Coastal peoples fish and trade. Mountain peoples mine and defend. Steppe peoples ride and raid. Before you build a culture, build the land that made them.

This skill holds the principles of physical world design — not the specific geography of any single world (that lives in the world-bible), but the methodology for building geography that generates interesting civilizations, conflicts, and stories.

## Core Principles

### Geography as Constraint

Geography is the deepest constraint in worldbuilding. It constrains civilization before anything else:

- **Water** determines where people settle. Rivers and coasts support dense populations. Deserts and mountains do not.
- **Arable land** determines where people eat. Fertile regions sustain empires. Barren regions sustain raiders, monks, and hermits.
- **Chokepoints** determine where people fight. Mountain passes, river crossings, narrow straits — these are where borders form and wars happen.
- **Isolation** determines where people diverge. Islands, valleys behind mountains, deep forests — these are where distinct cultures incubate.

### The Resource Gradient

The most powerful worldbuilding tool: place something valuable in a place that's hard to hold.

Resources that are evenly distributed don't create conflict. Resources concentrated in one place create empires. Resources concentrated in a place that's geographically defensible create independent powers. Resources that require two geographically separated materials to be useful create trade — and trade creates civilization.

**Key question for any world**: What is scarce, where is it found, and what does it cost to move it?

### Climate as Character

Climate isn't just weather — it's the mood of a region made physical:

| Climate | Civilization Character | Narrative Mood |
|---------|----------------------|----------------|
| Tropical / lush | Abundance, stratification, decay, rebirth cycles | Fecund, overwhelming, entropy |
| Arid / desert | Efficiency, fundamentalism, nomadism, oasis politics | Stark, unforgiving, sacred |
| Temperate | Balance, agriculture, cities, institutional complexity | Measured, historic, layered |
| Arctic / tundra | Scarcity, community bonds, oral tradition, survival focus | Endurance, isolation, purity |
| Volcanic / unstable | Fatalism, spiritual intensity, innovation born of necessity | Urgency, impermanence, power |

### Biomes as Story Engines

Each biome creates its own narrative potential:

- **Forests**: Concealment, ancient things, boundary between known and unknown. Forests are where the rules of civilization weaken.
- **Mountains**: Barriers, treasure, verticality as metaphor. Mountain cultures look down on flatlands, literally and figuratively.
- **Oceans**: Connection and separation simultaneously. An ocean is a wall until someone builds a ship; then it's a highway.
- **Rivers**: The arteries of civilization. Follow a river and you follow the history of every culture that lived along it.
- **Deserts**: Absence that reveals essence. Desert cultures are distilled — everything unnecessary has been burned away.
- **Swamps / Wetlands**: Transition zones. Not land, not water. Culturally, these become places of liminality, secrecy, and resistance.

## Building a Physical World

### Step 1: Establish Scale

How big is the setting? This determines travel time, which determines political cohesion, which determines everything.

| Scale | Travel Time (pre-industrial) | Political Implication |
|-------|------------------------------|----------------------|
| City-state | Hours | Direct governance, face-to-face politics |
| Region | Days to weeks | Governor systems, local autonomy |
| Continent | Months | Empires fragment, regional cultures diverge |
| Global | Years | No true central authority, trade empires |

### Step 2: Place Water First

Rivers and coastlines are the skeleton of civilization. Place them before anything else:
- Major rivers define agricultural heartlands
- Coastlines define trade networks
- Confluences (where rivers meet) are where cities grow
- Watersheds (where water divides) are natural borders

### Step 3: Place Barriers

Mountains, deserts, deep forests, and oceans separate populations. Barriers create:
- Linguistic drift (isolation → distinct languages over time)
- Cultural divergence (different problems → different solutions)
- Military chokepoints (defensible positions → political boundaries)

### Step 4: Place Resources

After water and barriers, distribute the resources that matter in this world:
- **Basic resources** (food, water, timber) — determines where people can live
- **Strategic resources** (metals, rare materials, fantasy-system fuel) — determines who has power
- **The resource your world cares about most** — whatever the fantasy system runs on, or whatever the central conflict is about. Place it thoughtfully.

### Step 5: Let Geography Generate Culture

Now ask: given these mountains, rivers, resources, and barriers — what kind of civilizations would *inevitably* arise? The best cultures feel inevitable given their geography. They shouldn't need to be explained; the map should explain them.

## Ecology

For deep ecosystem design (the Getz 10-niche model, complete food webs, fantasy ecology), reference the `ecology-design` skill. This section covers the basics of how ecology shapes civilization.

### The Food Web Shapes the World

What lives in a region determines what people eat, wear, build with, and worship:

- Herding cultures form where large herbivores are domesticable
- Fishing cultures form along productive coastlines and rivers
- Agricultural cultures form where grain crops thrive
- Hunter-gatherer cultures persist where farming is impractical but game is abundant

### Fantasy Ecology

If the fantasy system affects living things, the ecology is fundamentally different:

- **Magical fauna** — creatures that use the fantasy system. They create ecological niches that don't exist in our world.
- **Corrupted zones** — areas where the fantasy system has gone wrong. These are wastelands with their own warped ecology.
- **Resource organisms** — living things that produce or concentrate fantasy-system resources. These become the most valuable creatures in the world, hunted or farmed accordingly.

## Common Mistakes

1. **Geography that serves the plot but doesn't make sense.** A convenient mountain range exactly where you need a border. Instead: let the geography generate the borders, and adjust the plot.
2. **Flat worlds.** Everything is temperate forest with different flags. Push for variety — a world with three biomes is more interesting than one with one.
3. **Resources that don't matter.** If a resource exists on the map but nobody fights over it, trades it, or depends on it, it's decoration. Every resource should create at least one relationship.
4. **Ignoring the fantasy system's geographic impact.** If magic comes from crystals underground, the geology of your world is the most important map. If it comes from sunlight, latitude matters. The fantasy system reshapes geography.