gds-gdd

Invoke the skill with your game concept and it runs a discovery phase covering game type, existing inputs, scope, and downstream needs before drafting. You choose express mode for a fast full draft or facilitative mode to walk pillars, core loop, and mechanics section by section.

The canonical template covers Executive Summary, Target Audience, Goals, Core Gameplay (pillars, loop, win/loss), Game Mechanics, genre-specific sections, Progression and Balance, Level Design, Art and Audio, Technical Specifications, Development Epics, Success Metrics, Out of Scope, and Assumptions.

A validator subagent walks a checklist covering information density, measurability, traceability, engine-leakage discipline, genre compliance, and structural integrity. Findings are rendered into an HTML report with a grade plus a Markdown companion via the render-validation-html.py script.

Yes. It matches your pitch against a game-types taxonomy and genre-complexity ratings, then loads a genre guide that scaffolds required subsections such as RPG stat systems and save models or roguelike run structure and seed determinism.

Use a PRD only when you need formal functional and non-functional requirements or PRD-format output for an external tool. The GDD is the canonical design artifact owning mechanics, levels, art, audio, and progression; the skill itself suggests the PRD skill when that fits better.

Yes. In headless mode it infers intent and game type from provided inputs, completes the work without asking questions, and ends with a JSON status block listing produced artifacts, assumptions, and open questions.