gat-design

Design

This skill writes all design and art documents.

Phase 1: Resolve Mode

Check existing files:

• If design/gdd/game.md missing → Mode: wizard
• If argument matches a system name in systems-index.md → Mode: system
• If game.md exists and at least one system in systems-index.md lacks a GDD → Mode: continue
• If game.md exists and all systems have GDDs → report design is complete, stop

Treat any non-system-name argument as a concept hint passed into the wizard.

Phase 2: Wizard

Skip this phase if Mode is continue or system.

Step 1 — Core Concept

If a concept hint was provided, first spawn gat-designer to extract what is already answered from the hint:

• genre / style
• core player verb
• target feeling
• rough scope

Then use AskUserQuestion to ask only the questions the hint did not answer. If the hint answered all four, skip Step 1 entirely and proceed to Step 2.

Step 2 — Concept Direction

Spawn gat-designer to generate 2-3 short concept directions (3-5 sentences each) based on Step 1 answers.

Use AskUserQuestion:

• "Which direction resonates most, or describe your own?"
• Options: present the 2-3 directions as options plus "Describe my own"

Step 3 — System Scope

Spawn gat-designer to propose a system list with brief rationale for each, based on the chosen direction.

Use AskUserQuestion (multiSelect):

• "Which systems should be in scope?"
• List the proposed systems as options

Then use a second AskUserQuestion:

• "Any systems to add that are missing? (leave blank to continue)"

Step 4 — Confirm Before Writing

Show a one-paragraph summary: chosen direction + confirmed system list.

Use AskUserQuestion:

• "Ready to write the design docs?"
• Options: Yes, write them (Recommended) / Let me adjust something

If user wants to adjust, loop back to the relevant step.

Phase 3: Execute

Read templates:

• .claude/docs/templates/design/game-overview.md
• .claude/docs/templates/design/systems-index.md
• .claude/docs/templates/design/system-gdd.md
• .claude/docs/templates/design/global-art.md
• .claude/docs/templates/design/system-art.md
• .claude/docs/templates/design/content-data.md

Wizard or Continue mode

If Mode is wizard: execute Steps 1-5 below in order. If Mode is continue: skip Steps 1-2, go directly to Step 3.

Step 1 — Spawn gat-designer to write design/gdd/game.md and design/gdd/systems-index.md:

• Pass wizard answers (direction, confirmed system list)
• Pass templates
• Instruction: write both files in one pass

Step 2 — Spawn gat-artist to write design/art/art-direction.md:

• Pass game.md, global-art template
• Pass existing art-direction.md if present

Ask after Step 2 complete - After step 2 complete, Let user confirm changes:

Use AskUserQuestion:

• "Do you want to change the design docs? Or continue to next step?"
• Options: Yes, continue to next step / Let me adjust something

Step 3 — For each system in systems-index.md lacking a GDD, in order:

Spawn gat-designer → design/gdd/<system>.md:

• Pass game.md, systems-index.md, system-gdd template
• Pass existing system GDD if present

Step 4 — Content Fill (for systems with high content volume)

For each system whose system GDD is complete AND which requires substantial content data, spawn gat-designer to write design/content/<system>-data.md:

• Pass the system GDD, game.md, systems-index.md, content-data template
• Pass existing content doc if present
• The content doc fills specific instances, parameters, sequences, and groups — the data that instantiates the rules defined in the system GDD

A system needs a content-data doc when its GDD defines data structures that need many concrete instances (e.g. an enemy GDD defines enemy attributes → content doc fills 25+ specific enemies; a stage GDD defines wave scheduling → content doc fills wave-by-wave scripts for all 5 stages).

Systems that are purely mechanical (e.g. input, tbs-scoring) typically do NOT need content-data docs — their parameters fit within the GDD itself.

Step 5 — For each system in systems-index.md lacking an art doc, in order:

Spawn gat-artist → design/art/<system>-art.md:

• Pass game.md, art-direction.md, the system GDD, the content-data doc (if it exists), system-art template
• Pass existing system art doc if present
• The artist now has both the GDD (rules/schema) and the content-data doc (specific instances) to design complete visuals

System mode

Require design/gdd/game.md and design/gdd/systems-index.md.

Step 1 — Spawn gat-designer → design/gdd/<system>.md

Step 2 — If the system needs content data, spawn gat-designer → design/content/<system>-data.md

Step 3 — Spawn gat-artist → design/art/<system>-art.md (pass GDD + content-data if exists)

Phase 4: Review

Summarize what was created or updated.

Use AskUserQuestion:

• Plan milestones (Recommended) → Run /gat-milestone
• Add another system → Run /gat-design <name>
• Stop here