--- name: game-architect description: READ this skill when designing or planning any game system architecture — including combat, skills, AI, UI, multiplayer, narrative, or scene systems. Contains paradigm selection guides (DDD / Data-Driven / Prototype), system-specific design references, and mixing strategies. Works as a domain knowledge plugin alongside workflow skills (OpenSpec, SpecKit) or plan mode of an agent. ---

# Game Architect Skill

Game architecture domain knowledge reference. Provides paradigm selection, system design references for game project architecture.

> [!NOTE] > This skill contains **domain knowledge only**, not a workflow. Pair it with a workflow skill (e.g., OpenSpec, SpecKit) or an agent's plan mode for structured design flow.

## Usage Modes

### With Workflow Skill (Recommended)

When used with a workflow skill (e.g., OpenSpec, SpecKit) or in the plan mode of an agent, this skill serves as a domain knowledge plugin:

- **During requirements/spec phases**: Consult the Paradigm Selection Guide and System-Specific References to inform architectural decisions - **During design/planning phases**: Use the Reference Lookup Guide below to read relevant `references/` documents

### Knowledge Mode (Query)

When user requests to query knowledge for game architecture, this skill provides a reference lookup guide to relevant `references/` documents based on the task.

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## Reference Lookup Guide

When designing game architecture, read the relevant `references/` documents based on the task:

### Architecture References

| When | Read | |------|------| | Always (high-level structure) | `references/macro-design.md` | | Always (core principles) | `references/principles.md` | | Requirement analysis | `references/requirements-analysis.md` | | Choosing DDD paradigm | `references/domain-driven-design.md` | | Choosing Data-Driven paradigm | `references/data-driven-design.md` | | Choosing Prototype paradigm | `references/prototype-design.md` | | Evolution & extensibility review | `references/evolution.md` | | Changing requirements in an existing implementation | `references/requirement-change-strategy.md` | | Performance optimization needed | `references/performance-optimization.md` | | Multiplayer support needed | `references/multiplayer-overview.md` |

- For physical architecture design, see the Physical Architecture References table below. - For system-specific design, see the System-Specific References table below. - For multiplayer system design, see the Multiplayer References table below.

Note : Only read the multiplayer references when multiplayer is needed.

### Physical Architecture References

| When | Read | |------|------| | Project structure & file organization | `references/project-structure.md` | | Data formats, processing, custom formats, bundles, metadata | `references/data-files.md` | | Gameplay content editor applications and authoring pipelines | `references/content-editor.md` | | Asset conventions & pipeline | `references/asset-conventions.md` | | Distribution, packaging, hot update, CDN, deployment | `references/distribution.md` |

### System-Specific References

| System Category | Reference | |----------------|-----------| | Foundation & Core (Logs, Timers, Modules, Events, Resources, Audio, Input) | `references/system-foundation.md` | | Time & Logic Flow (Update Loops, Async, FSM, Command Queues, Controllers) | `references/system-time.md` | | Combat & Scene (Scene Graphs, Spatial Partitioning, ECS/EC, Loading) | `references/system-scene.md` | | UI & Modules (Modules Management, MVC/MVP/MVVM, UI Management, Data Binding, Reactive) | `references/system-ui.md` | | Skill System (Attribute, Skill, Buff) | `references/system-skill.md` | | Action Combat System (HitBox, Damage, Melee, Projectiles) | `references/system-action-combat.md` | | Camera, Character & Controller 3C (PlayerController, Physics, Camera, Actor States) | `references/system-3c.md` | | Effect & Feedback System (Screen Shake, VFX, Hit-Stop, Haptics, SFX, Floating Text, UI Feedback, Orchestration) | `references/system-effect-feedback.md` | | Narrative System (Dialogue, Cutscenes, Story Flow) | `references/system-narrative.md` | | Game AI System (Movement, Pathfinding, Decision Making, Tactical) | `references/system-game-ai.md` | | Mod & DLC System (Plugin Architecture, Config Database, Scripting, Hooks, Extensibility) | `references/system-mod.md` | | Procedural Content Generation (PCG) (World/Level Generation, Roguelike, Noise, Simulation) | `references/system-pcg.md` | | Algorithm & Data Structures (Pathfinding, Search, Physics, Generic Solver) | `references/algorithm.md` | | Puzzle Game System (Match-3, Jigsaw, Water Sort, Blocks, Physics Puzzles, Board Games, Content & Presentation Boundaries) | `references/system-puzzle.md` |

### Multiplayer References

| Focus | Reference | Use When | |------|------|------| | Multiplayer overview | `references/multiplayer-overview.md` | Decide client/server responsibility, authority split, and gameplay sync style | | Multiplayer protocol and connection | `references/multiplayer-protocol.md` | Design messages, serialization, Req/Resp/Notify, heartbeat, reconnect | | Multiplayer server architecture | `references/multiplayer-server-architecture.md` | Design ownership boundaries, process roles, deployment, persistence, recovery | | Common server components and services | `references/multiplayer-implementation-common.md` | Build shared infrastructure such as auth, gateway, connector, db, cache, discovery, queue, observability | | Room server build playbook | `references/multiplayer-implementation-room.md` | Build a concrete small-to-medium room-based realtime server with join flow, room ownership, settlement, reconnect | | Encounter server build playbook | `references/multiplayer-implementation-encounter.md` | Build a concrete turn-based or combat-workflow server with checkpointing, idempotent actions, settlement | | Persistent world server build playbook | `references/multiplayer-implementation-world.md` | Build a concrete AOI world server with region ownership, transfer, location registry, reconnect | | Deterministic sync, lockstep, and rollback | `references/multiplayer-deterministic-sync.md` | Design deterministic input-sync architectures, frame pipelines, rollback, replay, and desync handling | ---

## Paradigm Selection Guide

| Paradigm | KeyPoint | Applicability Scope | Examples | Reference | | :--- | :--- | :--- | :--- | :--- | | **Domain-Driven Design (DDD)** | OOP & Entity First | High Rule Complexity. <br> Rich Domain Concepts. <br> Many Distinct Entities. | Core Combat Logic, Physics Interactions, Damage/Buff Rules, Complex AI Decision. | `references/domain-driven-design.md` | | **Data-Driven Design** | Data Layer First | High Content Complexity. <br> Flow Orchestration. <br> Simple Data Management. | **Content**: Quests, Level Design.<br>**Flow**: Tutorial Flow, Skill Execution, Narrative.<br>**Mgmt**: Inventory, Shop, Mail, Leaderboard. | `references/data-driven-design.md` | | **Use-Case Driven Prototype** | Use-Case Implementation First | Rapid Validation | Game Jam, Core Mechanic Testing. | `references/prototype-design.md` |

Here, **Data-Driven Design** means a **data-structure-first programming paradigm**, not specifically configuration-driven gameplay. See `references/data-driven-design.md` for the full terminology boundary.

### Mixing Paradigms

Most projects mix paradigms: 1. **Macro Consistency**: All modules follow the same Module Management Framework. 2. **Domain for Core Entities & Rules**: Use DDD for systems with high rule complexity, rich domain concepts, and many distinct entities (e.g., Combat Actors, Damage Formulas, AI Decision). 3. **Data for Content, Flow & State**: Use Data-Driven for expandable content (Quests, Level Design), flow orchestration (Tutorial, Skill Execution, Narrative), and simple data management (Inventory, Shop). 4. **Hybrid Paradigms**: - 4.1 **Entities as Data**: Domain Entities naturally hold both data (fields) and behavior (methods). Design entities to be serialization-friendly (use IDs, keep state as plain fields) so they serve both roles without a separate data layer. - 4.2 **Flow + Domain**: Use data-driven flow to orchestrate the sequence/pipeline, domain logic to handle rules at each step. E.g., Skill System: flow drives cast→channel→apply, domain handles damage calc and buff interactions. - 4.3 **Separate Data/Domain Layers**: Only when edit-time and runtime representations truly diverge. Use a Bake/Compile step to bridge them. E.g., visual node-graph editors, compiled assets. 5. **Paradigm Interchangeability**: Many systems can be validly implemented with either paradigm. E.g., Actor inheritance hierarchy (Domain) ↔ ECS components + systems (Data-Driven); Buff objects with encapsulated rules (Domain) ↔ Tag + Effect data entries resolved by a generic pipeline (Data-Driven). See **Selection Criteria** table above for trade-off signals. 6. **Integration**: Application Layer bridges different paradigms.

### Selection Criteria

When both DDD and Data-Driven fit, use these signals:

| Signal | Favor DDD | Favor Data-Driven | |--------|-----------|-------------------| | Entity interactions | Complex multi-entity rules (attacker × defender × buffs × environment) | Mostly CRUD + display, few cross-entity rules | | Behavior source | Varies by entity type, hard to express as pure data | Driven by config tables, designer-authored content | | Change frequency | Rules change with game balance iterations | Content/flow changes far more often than logic | | Performance profile | Acceptable overhead for rich object graphs | Needs batch processing, cache-friendly layouts | | Networking | Stateful objects acceptable | Flat state snapshots preferred (sync, rollback) | | Team workflow | Programmers own the logic | Designers need to iterate without code changes |

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