What is unity-writing-gdd?

A framework for creating and maintaining game design documents, or organized plans for how a game works.

Use it to start, audit, consolidate, and version a game design document, or write feature documents and design pillars.

It helps turn scattered game ideas and design notes into consistent project documentation.

unity-writing-gdd — Skill for Claude Code by sonereraslan

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 sonereraslan/local-marketplace --skill unity-writing-gdd

Clone the repo

git clone --depth 1 https://github.com/sonereraslan/local-marketplace

Made for: Claude Code.

Or install superunity-design, the plugin that ships this one along with the rest of its 10 skills, 5 agents.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/sonereraslan/local-marketplace/unity-writing-gdd/github.svg)](https://agentmods.dev/skills/sonereraslan/local-marketplace/unity-writing-gdd)

Your own site

<a href="https://agentmods.dev/skills/sonereraslan/local-marketplace/unity-writing-gdd"><img src="https://agentmods.dev/badge/skills/sonereraslan/local-marketplace/unity-writing-gdd/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/sonereraslan/local-marketplace/unity-writing-gdd"><img src="https://agentmods.dev/badge/skills/sonereraslan/local-marketplace/unity-writing-gdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 136 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,505 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.

Model	Per session	Once invoked
Fable 5.1	$0.00136	$0.02505
Opus 5.5	$0.00054	$0.01002
Sonnet 5.5	$0.00027	$0.00501
Haiku 4.5	$0.00014	$0.00250

Measured 2mo ago against content hash f52d8910b50f, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

unity-writing-gdd 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 2mo 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.

plugins/superunity-design/skills/unity-writing-gdd/SKILL.md · 336 lines

How it starts

The opening of the file, as written. The whole thing — 336 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Unity Game Planner

Professional game documentation framework — structure, audit, and consolidate GDDs to industry standard

When to Use This Skill

Starting a new GDD from scratch
Writing a Feature Document for a specific system
Defining or reviewing design pillars
Auditing an existing GDD for completeness
Consolidating scattered design notes into one unified document
Managing GDD versioning and terminology consistency

For design theory and constraints (pillars, mechanics framework, anti-patterns) use unity-designer. For generating design ideas use unity-brainstorming.

Usage Patterns

"GDD init"              -> Initialise a new project GDD from scratch
"GDD audit"             -> Audit an existing GDD for completeness
"GDD consolidate"       -> Merge scattered design docs into a single GDD
"feature doc [name]"    -> Generate a Feature Document for a system
"design pillars"        -> Define or review the project's design pillars
"balance template"      -> Generate a numerical balance design template

GDD Core Philosophy

Industry consensus: there is no single standard format, but these principles apply universally:

Principle	What it means
Living Document	Continuously updated — not a one-time deliverable
Agile & Lightweight	Avoid hundred-page documents nobody reads
Findable	Information must be locatable within seconds
Visual	Games are a visual medium — documents should use diagrams, tables, and visuals

Two-Layer Architecture

+--------------------------------------------------------+
|  Master Document                                        |
|  +-- Executive summary, vision, design pillars         |
|  +-- Core gameplay overview                            |
|  +-- Links to all Feature Documents                    |
+--------------------------------------------------------+
                          |
+--------------------------------------------------------+
|  Feature Documents (one per major system)               |
|  +-- Combat system                                     |
|  +-- Character system                                  |
|  +-- Economy system                                    |
|  +-- Movement system                                   |
|  +-- ...                                               |
+--------------------------------------------------------+

Read the full file on GitHub · 336 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.

2mo ago First seen · 336 lines · 136 tokens per session scan A f52d8910b50f

Subscribe to this mod's changes

unity-writing-gdd is a skill published in the GitHub repository sonereraslan/local-marketplace (2 stars, last pushed 6mo ago), licensed MIT. It adds 136 tokens to every session and 2,505 once invoked, about $0.0005 per session on Opus 5.5. 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 2026-08-31.

Game development Writing and docs

unity-writing-gdd next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
unity-writing-gddsonereraslan/local-marketplace	Skill	2	6mo ago	MIT	A	136	Claude Code
playtest-reportDonchitos/Claude-Code-Game-Studios	Skill	36k	19d ago	MIT	A	20	Claude Code
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motionOpenDCAI/GameFactory-3A	Skill	1.0k	8d ago	Apache-2.0	A	0	Claude Code, Codex
unity-addressablesBesty0728/Unity-Skills	Skill	1.9k	yesterday	MIT	A	25	Claude Code, Codex
unity-manual-componentBesty0728/Unity-Skills	Skill	1.9k	yesterday	MIT	A	36	Claude Code, Codex