Guided, section-by-section GDD authoring for a single game system. Gathers context from existing docs, walks through each required section collaboratively, cross-references dependencies, and writes incrementally to file.

! bash "${CLAUDE SKILL DIR}/../../hooks/yaml helper.sh" resolve config keys review mode,automation,workflow,docs.density,system overrides Resolved above — use as is; review overrides review mode . No block → defaults in .claude/docs/config resolution.md . Design System When this skill is invoked: 1. Parse Arguments & Validate Read references/1 parse arguments.md now and follow it — this phase's steps are in that file, not here. Read it again if the conversation was compacted or resumed during this phase. 2. Gather Context (Read Phase) Read references/2 gather context.md now and follow it — this phase's steps are in that file, not here. Read it again if the conversation was compacted or resumed during this phase. 3. Create File Skeleton Read references/3 file skeleton.md now and follow it — this phase's steps are in that file, not here. Read it again if the conversation was compacted or resumed during this phase. 4. Section by Section Design Read references/4 section design.md now and follow it — this phase's steps are in that file, not here. Read it again if the conversation was compacted or resumed during this phase. 5. Post Design Validation Read references/5 post design.md now and follow it — this phase's steps are in that file, not here. Read it again if the conversation was compacted or resumed during this phase. 6. Specialist Agent Routing This skill delegates to specialist agents for domain expertise. The main session orchestrates the overall flow; agents provide expert content. Rows here are finer grained than the nine Category values on purpose — the right specialist for combat is not the right specialist for pathfinding, and both are Gameplay . Resolve in two steps: take the system's Category from systems index.md , then pick the row within it that matches what the system actually does. Every category has at least one row, so nothing falls through. Category Rows below to choose from Gameplay Combat/damage/health · AI/pathfinding/behavior · Animation/character movement · Character systems · Camera/input/controls Core Foundation/Infrastructure · Camera/input/controls Persistence Foundation/Infrastructure Economy Economy/loot/crafting Progression Progression/XP/skills UI UI systems · Visual effects (when the system is HUD adjacent VFX) Audio Audio systems Narrative Dialogue/quests/lore Meta Foundation/Infrastructure (analytics, tutorial plumbing) · UI systems (accessibility options screens) If two rows fit, spawn the union of their Primary agents and say why. System type Primary Agent Supporting Agent(s) Foundation/Infrastructure (event bus, save/load, scene mgmt, service locator) systems designer gameplay programmer (feasibility), engine programmer (engine integration) Combat, damage, health game designer systems designer (formulas), ai programmer (enemy AI), art director (hit feedback visual direction, VFX intent) Economy, loot, crafting economy designer systems designer (curves), game designer (loops) Progression, XP, skills game designer systems designer (curves), economy designer (sinks) Dialogue, quests, lore game designer narrative director (story), writer (content), art director (character visual profiles, cinematic tone) UI systems (HUD, menus) game designer ux designer (flows), ui programmer (feasibility), art director (visual style direction), technical artist (render/shader constraints) Audio systems game designer audio director (direction), sound designer (specs) AI, pathfinding, behavior game designer ai programmer (implementation), systems designer (scoring) Level/world systems game designer level designer (spatial), world builder (lore) Camera, input, controls game designer ux designer (feel), gameplay programmer (feasibility) Animation, character movement game designer art director (animation style, pose language), technical artist (rig/blend constraints), gameplay programmer (feel) Visual effects, particles, shaders game designer art director (VFX visual direction), technical artist (performance budget, shader complexity), systems designer (trigger/state integration) Character systems (stats, archetypes) game designer art director (character visual archetype), narrative director (character arc alignment), systems designer (stat formulas) When delegating via the Agent tool : Provide: system name, game concept summary, dependency GDD excerpts, the specific section being worked on, and what question needs expert input The agent returns analysis/proposals to the main session The main session presents the agent's output to the user via AskUserQuestion The user decides; the main session writes to file Agents do NOT write to files directly — the main session owns all file writes 7. Recovery & Resume If the session is interrupted (compaction, crash, new session): 1. Read production/session state/active.md — it records the current system and which sections are complete 2. Read design/gdd/[system name].md — sections with real content are done; sections with [To be designed] still need work. Read it by section: find the headings with the Grep tool (pattern ^ , content mode) and Read those ranges with offset and limit. 3. Resume from the next incomplete section — no need to re discuss completed ones This is why incremental writing matters: every approved section survives any disruption. Collaborative Protocol In collaborative mode (the default). For guided and autonomous modes, see the per mode rules in .claude/docs/automation modes.md — the "Never" lines below describe what collaborative mode requires, not what applies universally. This skill follows the collaborative design principle at every step: 1. Question Options Decision Draft Approval for every section 2. AskUserQuestion at every decision point (Explain Capture pattern): Phase 2: "Ready to start, or need more context?" Phase 3: "May I create the skeleton?" Phase 4 (each section): Design questions, approach options, draft approval Phase 5: "May I update the entity registry? May I update the systems index? What's next?" — not "Run design review?": §5c forbids offering /design review inline, because the reviewing agent must not inherit this session's design history. Phase 5c presents the hand off; it never asks. 3. "May I write to [filepath]?" before the skeleton and before each section write 4. Incremental writing : Each section is written to file immediately after approval 5. Session state updates : After every section write 6. Cross referencing : Every section checks existing GDDs for conflicts 7. Specialist routing : Complex sections get expert agent input, presented to the user for decision — never written silently Never auto generate the full GDD and present it as a fait accompli. Never write a section without user approval. Never contradict an existing approved GDD without flagging the conflict. Always show where decisions come from (dependency GDDs, pillars, user choices). Context Window Awareness This is a long running skill. After writing each section, check if the status line shows context at or above 70%. If so, append this notice to the response: Context is approaching the limit (≥70%). Your progress is saved — all approved sections are written to design/gdd/[system name].md . When you're ready to continue, open a fresh Claude Code session and run /design system [system name] — it will detect which sections are complete and resume from the next one. Recommended Next Steps Run /design review design/gdd/[system name].md in a fresh session to validate the completed GDD independently Run /consistency check to verify this GDD's values don't conflict with other GDDs Run /map systems next to move to the next highest priority undesigned system Run /gate check technical setup when all MVP GDDs are authored and reviewed

design-system