map-systems

When this skill is invoked:

## Parse Arguments

Two modes:

- **No argument**: `/map-systems` — Run the full decomposition workflow (Phases 1-5)
  to create or update the systems index.
- **`next`**: `/map-systems next` — Pick the highest-priority undesigned system
  from the index and hand off to `/design-system` (Phase 6).

Also resolve the review mode (once, store for all gate spawns this run):
1. If `--review [full|lean|solo]` was passed → use that
2. Else read `production/review-mode.txt` → use that value
3. Else → default to `lean`

See `.claude/docs/director-gates.md` for the full check pattern.

---

## Phase 1: Read Concept (Required Context)

Read the game concept and any existing design work. This provides the raw material
for systems decomposition.

**Required:**
- Read `design/gdd/game-concept.md` — **fail with a clear message if missing**:
  > "No game concept found at `design/gdd/game-concept.md`. Run `/brainstorm` first
  > to create one, then come back to decompose it into systems."

**Optional (read if they exist):**
- Read `design/gdd/game-pillars.md` — pillars constrain priority and scope
- Read `design/gdd/systems-index.md` — if exists, **resume** from where it left off
  (update, don't recreate from scratch)
- Glob `design/gdd/*.md` — check which system GDDs already exist

**If the systems index already exists:**
- Read it and present current status to the user
- Use `AskUserQuestion` to ask:
  "The systems index already exists with [N] systems ([M] designed, [K] not started).
  What would you like to do?"
  - Options: "Update the index with new systems", "Design the next undesigned system",
    "Review and revise priorities"

---

## Phase 2: Systems Enumeration (Collaborative)

Extract and identify all systems the game needs. This is the creative core of the
skill — it requires human judgment because concept docs rarely enumerate every
system explicitly.

### Step 2a: Extract Explicit Systems

Scan the game concept for directly mentioned systems and mechanics:
- Core Mechanics section (most explicit)
- Core Loop section (implies what systems drive each loop tier)
- Technical Considerations section (networking, procedural generation, etc.)
- MVP Definition section (required features = required systems)

### Step 2b: Identify Implicit Systems

For each explicit system, identify the **hidden systems** it implies. Games always
need more systems than the concept doc mentions. Use this inference pattern:

- "Inventory" implies: item database, equipment slots, weight/capacity rules,
  inventory UI, item serialization for save/load
- "Combat" implies: damage calculation, health system, hit detection, status effects,
  enemy AI, combat UI (health bars, damage numbers), death/respawn
- "Open world" implies: streaming/chunking, LOD system, fast travel, map/minimap,
  point of interest tracking, world state persistence
- "Multiplayer" implies: networking layer, lobby/matchmaking, state synchronization,
  anti-cheat, network UI (ping, player list)
- "Crafting" implies: recipe database, ingredient gathering, crafting UI,
  success/failure mechanics, recipe discovery/learning
- "Dialogue" implies: dialogue tree system, dialogue UI, choice tracking, NPC
  state management, localization hooks
- "Progression" implies: XP system, level-up mechanics, skill tree, unlock
  tracking, progression UI, progression save data

Explain in conversation text why each implicit system is needed (with examples).

### Step 2c: User Review

Present the enumeration organized by category. For each system, show:
- Name
- Category
- Brief description (1 sentence)
- Whether it was explicit (from concept) or implicit (inferred)

Then use `AskUserQuestion` to capture feedback:
- "Are there systems missing from this list?"
- "Should any of these be combined or split?"
- "Are there systems listed that this game does NOT need?"

Iterate until the user approves the enumeration.

---

## Phase 3: Dependency Mapping (Collaborative)

For each system, determine what it depends on. A system "depends on" another if
it cannot function without that other system existing first.

### Step 3a: Map Dependencies

For each system, list its dependencies. Use these dependency heuristics:
- **Input/output dependencies**: System A produces data System B needs
- **Structural dependencies**: System A provides the framework System B plugs into
- **UI dependencies**: Every gameplay system has a corresponding UI system that
  depends on it (but UI is designed after the gameplay system)

### Step 3b: Sort by Dependency Order

Arrange systems into layers:
1. **Foundation**: Systems with zero dependencies (designed and built first)
2. **Core**: Systems depending only on Foundation systems
3. **Feature**: Systems depending on Core systems
4. **Presentation**: UI and feedback systems that wrap gameplay systems
5. **Polish**: Meta-systems, tutorials, analytics, accessibility

### Step 3c: Detect Circular Dependencies

Check for cycles in the dependency graph. If found:
- Highlight them to the user
- Propose resolutions (interface abstraction, simultaneous design, breaking the
  cycle by defining a contract between the two systems)

### Step 3d: Present to User

Show the dependency map as a layered list. Highlight:
- Any circular dependencies
- Any "bottleneck" systems (many others depend on them — these are high-risk)
- Any systems with no dependents (leaf nodes — lower risk, can be designed late)

Use `AskUserQuestion` to ask: "Does this dependency ordering look right? Any
dependencies I'm missing or that should be removed?"

**Review mode check** — apply before spawning TD-SYSTEM-BOUNDARY:
- `solo` → skip. Note: "TD-SYSTEM-BOUNDARY skipped — Solo mode." Proceed to priority assignment.
- `lean` → skip (not a PHASE-GATE). Note: "TD-SYSTEM-BOUNDARY skipped — Lean mode." Proceed to priority assignment.
- `full` → spawn as normal.

**After dependency mapping is approved, spawn `technical-director` via Task using gate TD-SYSTEM-BOUNDARY (`.