setup-engine

name	setup-engine
description	Choose a game engine or runtime direction and create a project technical-preferences document from the canonical gamedev template.
argument-hint	[runtime-or-engine] [version-or-language]
user-invocable	true

Purpose: Choose a game engine or runtime direction and create the canonical project technical-preferences document.

Use when:

• a game project needs a runtime direction or a technical-preferences baseline
• the team needs one place for engine or runtime, target platforms, language, budgets, and tooling defaults

Do not use for:

• system decomposition
• writing individual system GDDs
• deep architecture ADR work

Inputs / Required Context:

• optional: design/gdd/game-concept.md
• required in guided mode: answers about 2D or 3D, target platforms, team experience, preferred language, licensing constraints
• optional explicit arguments: engine or runtime name plus version or language

Outputs / Owned Artifacts:

• owns docs/technical-preferences.md
• creates docs/ if it does not exist
• uses gamedev/templates/technical-preferences.md
• marks decisions as provisional when concept or platform context is incomplete

Modes or Arguments:

• guided: /setup-engine
• runtime only: /setup-engine web
• runtime spec: /setup-engine web typescript
• engine spec: /setup-engine unity 6
• engine spec: /setup-engine unreal 5.6

Execution Rules:

1. Read design/gdd/game-concept.md when it exists and extract project constraints, including any working or documentation language and player-facing language policy already fixed there.
2. In guided mode, ask only the minimum questions needed to narrow the engine or runtime choice.
3. If the version is missing, verify the latest stable release before using it; if it cannot be verified, mark it unresolved instead of guessing.
4. If the target runtime is browser-based, use Game Studio when available as the runtime-specialist source for stack-specific guidance instead of copying Phaser, Three.js, or browser-UI doctrine into this skill.
5. If the target runtime is not browser-based, rely on official engine docs or project-local specialists for engine-specific implementation details instead of inventing a parallel doctrine here.
6. Write or update docs/technical-preferences.md with runtime or engine, target platforms, language, conventions, performance budgets, testing defaults, approved addons, and the current language policy. If the concept already fixed the language policy, carry it forward instead of inventing a new one.
7. End with the next handoff in the flow: map-systems, then design-system, then prototype.

Failure / Stop Conditions:

• stop if guided answers are too thin to narrow the runtime choice and return a short comparison instead of forcing a decision
• do not invent platform, budget, or addon decisions that the project has not made

Return Format:

• chosen or shortlisted runtime or engine
• provisional or confirmed status
• output path
• specialist source used, if any
• critical open decisions
• next recommended skill: map-systems

Example Invocation:

• /setup-engine web typescript
• /setup-engine unity 6
• /setup-engine unreal 5.6

Related Skills / Boundary:

• use map-systems after engine setup to define the MVP design surface
• use browser specialists such as Game Studio only for browser-runtime depth; keep docs/technical-preferences.md as the canonical artifact here
• use architecture-decision later for durable technical choices beyond engine selection