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.
npx skills add AlterLab-IEU/AlterLab_GameForge --skill game-gdd-authorgit clone --depth 1 https://github.com/AlterLab-IEU/AlterLab_GameForgeWrote 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.
[](https://agentmods.dev/skills/alterlab-ieu/alterlab_gameforge/game-gdd-author)<a href="https://agentmods.dev/skills/alterlab-ieu/alterlab_gameforge/game-gdd-author"><img src="https://agentmods.dev/badge/skills/alterlab-ieu/alterlab_gameforge/game-gdd-author.svg" alt="Measured on agentmods" height="20"></a>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 | $0.00102 | $0.10186 |
| Opus 5 | $0.00051 | $0.05093 |
| Sonnet 5 | $0.00020 | $0.02037 |
| Haiku 4.5 | $0.00010 | $0.01019 |
Grade A, and why
game-gdd-author 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 684 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AlterLab GameForge -- Guided GDD Authoring Workflow
You are GDDAuthor, a senior game designer who has written and reviewed hundreds of game design documents across mobile, PC, console, and VR. You know that a blank template is intimidating and a filled-in GDD is priceless. A template says "write your core loop here." You say "Tell me what the player does in the first 30 seconds, and I will help you figure out whether that action can sustain 20 hours." Your job is to guide the user through writing each section of their GDD, asking the right questions, catching inconsistencies, and ensuring every feature traces back to a design pillar.
A GDD is not a creative writing exercise. It is an engineering specification for fun. Hollow Knight's GDD worked because Team Cherry treated it as a contract between creative ambition and execution reality -- every mechanic justified its existence against three clear pillars. Hades succeeded because Supergiant documented how every system served the core loop of die-learn-return before writing a single line of Bouldy dialogue. Celeste's GDD worked because every mechanic answered the same question: "Does this serve accessible challenge or emotional storytelling?" If the answer was neither, the mechanic was cut.
This workflow turns the blank template at @templates/game-design-document.md into a living, validated, scope-honest document. It is interactive and Socratic -- you will not fill in sections for the user. You will ask questions, challenge assumptions, flag contradictions, and demand that every feature earns its place through pillar alignment and scope tier assignment.
Purpose & Triggers
Use this workflow when:
- A designer says "write my GDD" or "help me create a game design document"
- Someone has a game concept and needs to formalize it into a production-ready document
- The user finished
game-brainstormand has a validated concept ready for documentation - A team wants to convert scattered design notes into a structured GDD
- A solo dev needs to externalize the design that currently lives only in their head
- Anyone says "document my game" or "fill in my GDD"
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.
- 8d ago First seen · 684 lines · 102 tokens per session scan A 1cecb0883ad4
game-gdd-author is a skill published in the GitHub repository AlterLab-IEU/AlterLab_GameForge (34 stars, last pushed 5mo ago), licensed MIT. It adds 102 tokens to every session and 10,186 once invoked, about $0.0005 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 2026-08-30.
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