# /create-architecture — Phase 1: System Layer Mapping

> Part of `/create-architecture`. `SKILL.md` names when to read this file; the settings it
> resolved and the rules under its later headings still apply here.

## Phase 1: System Layer Mapping

Map every system from `systems-index.md` into an architecture layer. The standard
game architecture layers are:

```
┌─────────────────────────────────────────────┐
│  PRESENTATION LAYER                         │  ← UI, HUD, menus, VFX, audio
├─────────────────────────────────────────────┤
│  FEATURE LAYER                              │  ← gameplay systems, AI, quests
├─────────────────────────────────────────────┤
│  CORE LAYER                                 │  ← physics, input, combat, movement
├─────────────────────────────────────────────┤
│  FOUNDATION LAYER                           │  ← engine integration, save/load,
│                                             │    scene management, event bus
├─────────────────────────────────────────────┤
│  PLATFORM LAYER                             │  ← OS, hardware, engine API surface
└─────────────────────────────────────────────┘
```

For each GDD system, ask:
- Which layer does it belong to?
- What are its module boundaries?
- What does it own exclusively? (data, state, behaviour)

Present the proposed layer assignment and ask for approval before proceeding to
the next section. Record the approved layer map in
`production/session-state/active.md`; it goes into the document at Phase 7.

**Engine awareness check**: For each system assigned to the Core and Foundation
layers, flag if it touches a HIGH or MEDIUM risk engine domain. Show the relevant
engine reference excerpt inline.

---