worldbuilding

worldbuilding is a skill for Claude Code, Codex from Wondermonger-daydreaming/claude-skills-library. It costs 213 tokens per session (1,483 once invoked), scanned A, original, MIT.

A worldbuilding method for silently developing the cultures, histories, places, beliefs, and systems behind a fictional setting.

In plain words
What is it for?
Use it to create fictional worlds, settings, societies, magic systems, economies, and political structures.
Why use it?
The hidden detail gives the visible parts of a world consistency and makes them feel lived-in rather than decorative.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to create fictional worlds, settings, societies, magic systems, economies, and political structures.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/wondermonger-daydreaming/claude-skills-library/worldbuilding
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Wondermonger-daydreaming/claude-skills-library --skill worldbuilding
Clone the repo
git clone --depth 1 https://github.com/Wondermonger-daydreaming/claude-skills-library

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for worldbuilding

README.md
[![agentmods](https://agentmods.dev/badge/skills/wondermonger-daydreaming/claude-skills-library/worldbuilding/github.svg)](https://agentmods.dev/skills/wondermonger-daydreaming/claude-skills-library/worldbuilding)
Your own site
<a href="https://agentmods.dev/skills/wondermonger-daydreaming/claude-skills-library/worldbuilding"><img src="https://agentmods.dev/badge/skills/wondermonger-daydreaming/claude-skills-library/worldbuilding/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for worldbuilding

Your own site · 80×15
<a href="https://agentmods.dev/skills/wondermonger-daydreaming/claude-skills-library/worldbuilding"><img src="https://agentmods.dev/badge/skills/wondermonger-daydreaming/claude-skills-library/worldbuilding.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 213 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,483 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00213 $0.01483
Opus 5 $0.00106 $0.00741
Sonnet 5 $0.00043 $0.00297
Haiku 4.5 $0.00021 $0.00148

Measured 9d ago against content hash 06ddeb97352d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

worldbuilding scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/worldbuilding/SKILL.md · 49 lines

How it starts

The opening of the file, as written. The whole thing — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Worldbuilding

Seed, not scripture

The source wraps this in lexical-demiurge rhapsody — a "silicon Scheherazade," a named collaborator, specific example-worlds, a mangaka case study. Strip the persona and the particular worlds. Don't recite the demiurge declamation or rebuild the source's specific settings; the franchise it analyzes is illustration, not template. What transfers is the discipline: the iceberg, the living-systems characters, the moves that make a world feel real. Build your own world; run the method on it.

The iceberg

The governing image: when you take a prompt, silently construct an entire world around it, like an iceberg — only a tiny piece peeks above the water; the majority stays hidden but underpins the whole. You build the cultures, histories, landscapes, cosmologies, and systems in full, knowing almost none of it will appear on the page. The submerged mass is not waste — it is the reason the visible tip feels load-bearing. A reader senses the unspoken depth they cannot see; that felt-density is what separates a lived-in world from a painted backdrop. The world that's all surface reads as a film set; the world with ninety percent underwater reads as real.

The core moves

  • Build the submerged mass. History that stretches back past the story, cultures with their own internal logic, geography that shapes the culture on it, economies and religions and power structures that cohere. Most of this never surfaces. Build it anyway — it is the ballast.
  • Reveal only the tip. The cardinal restraint. One concrete, specific detail implies a hundred unstated ones; an exposition-dump dredges the whole iceberg up and drowns the reader. Trust the reader to feel the mass from the tip. (This is /placement applied to worlds — the discipline of not explaining what you've built.)
  • Give systems rules, costs, limits. A power or magic system that can do anything has no stakes; a rule-bound one generates endless story precisely because it's constrained. Define what it costs, what it can't do, where it breaks. Constraint breeds generativity — the limits are the engine. (Constraints-as-tuning-forks; see /inventor-stance.)
  • Keep everything in coherent phase. Geography, history, language, economy, character, all singing together. Incoherence breaks immersion faster than implausibility does — readers forgive the fantastic but not the contradictory. Coherence is the binding force.
  • Let the world precede the plot. Build the world, then let the story emerge from its pressures — the tensions between its cultures, the costs of its systems — rather than imposing a plot and decorating it with setting. The richest stories are ones the world made inevitable.

Read the full file on GitHub · 49 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 49 lines · 213 tokens per session scan A 06ddeb97352d

Subscribe to this mod's changes

worldbuilding is a skill published in the GitHub repository Wondermonger-daydreaming/claude-skills-library (6 stars, last pushed 2mo ago), licensed MIT. It adds 213 tokens to every session and 1,483 once invoked, about $0.0011 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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