Design Diagram Authoring

Copy-ready Mermaid templates and authoring guidance for the four most common game-design diagrams. This skill ships templates + reference docs, not code analysis. Rendering is delegated to /t1k:preview.

When This Skill Triggers

• Starting a new GDD section that needs a visual (quest tree, economy, narrative, level)
• Sketching design intent before implementation
• Updating a design diagram alongside a gameplay change
• Need a Mermaid starting snippet that's more than a blank canvas

What This Skill Is NOT

• Not an adapter — does not parse code, does not implement detect(), does not register with the adapter-discovery scan
• Not a renderer — /t1k:preview --from-file <template> handles that via mermaid-cli
• Not prescriptive — templates are starting points; edit freely

The Four Templates

Template	Mermaid Type	Use For
templates/quest-tree.mmd	flowchart TD	Branching quest progression, prerequisites, hub-and-spoke structures
templates/economy-flow.mmd	flowchart LR	Currency sources (faucets) → sinks, conversion rates, inflation control
templates/narrative-branch.mmd	classDiagram	Character relationships + branching narrative lanes by Act/chapter
templates/level-spatial.mmd	flowchart LR	Level zones, gates (one-way vs two-way), spatial progression

Usage

1. Copy a template into your project

cp .claude/modules/design-base/skills/design-diagram-authoring/templates/quest-tree.mmd \
   docs/design/my-quest-tree.mmd

2. Edit the placeholders

Each template is heavily commented. Replace placeholder labels (Quest A, Gold, Act 1 Intro, Zone A) with your actual design.

3. Render with /t1k:preview

/t1k:preview --from-file docs/design/my-quest-tree.mmd

Or render inline:

/t1k:preview --diagram "quest tree for the prologue act"

4. Paste into your GDD

Render produces SVG/PNG. Embed in GDD markdown alongside the .mmd source so both are tracked in git.

Reference Docs (pattern guidance)

• references/quest-trees.md — linear / branch / hub-and-spoke / Act-based patterns
• references/economy-flows.md — faucet/sink distinction, conversion nodes, inflation leaks
• references/narrative-branches.md — decision vs outcome nodes, character arcs, consequence layering
• references/level-spatial.md — zones, gates, one-way edges, spatial vs logical adjacency

Scripts

• scripts/list-templates.cjs — lists the four template names (used by /t1k:find-skill and doctor integrity checks)

Rendering prerequisite

Install mermaid-cli once via the base preset:

t1k diagram install

The install.json in this skill advertises the dependency (requires: ["mermaid-cli"]) with isAdapter: false, so the installer rolls it up without registering the skill in adapter discovery.

Authoring tips

• Keep diagrams under ~30 nodes. Mermaid rendering degrades and designers stop reading beyond that.
• One diagram per concern. Split quest prerequisites and narrative branches into two diagrams even when they touch the same NPCs.
• Source of truth is the .mmd file. Never hand-edit rendered SVGs — edit the source and re-render.
• Comment intent, not mechanics. %% Act 1 gate — player must have fire talisman not %% edge from A to B.