This repository is a game-studio template. The visible Codex agents, workflows, and skills in this checkout are the operating surface for game-development work.
- Prompt surfaces declare both a concrete model and a reasoning effort; runtime derives only the model tier from the centralized model policy.
- Choose the model family by capability and blast radius: Sol for difficult/high-risk architecture, security, release, or cross-system decisions; Terra for bounded implementation, QA, docs, and production work; Luna for simple, repetitive, mechanical, or objectively verifiable work.
- Choose reasoning effort independently for each prompt surface. Valid combinations include Luna/medium for cheap-but-careful review, Terra/low for bounded routine work, Terra/high for difficult implementation, and Sol/medium when Sol capability is useful without maximum reasoning.
- Explicit user or task-tier overrides change the model family but preserve the selected surface's reasoning effort unless an escalation policy deliberately raises it.
- Designated fallback models are fixed by family: Sol to GPT-5.5, Terra to GPT-5.4, and Luna to GPT-5.4-mini; fallback execution keeps the selected surface effort.
After functional changes to game source, engine configuration, or assets, make a fresh documentation-impact decision before handoff:
- Update the owning `design/`, `docs/`, or `production/` document when player-visible behavior, architecture, production commitments, or release communication changed.
- Otherwise record `Decision: no-update`, `Documents: none`, and a specific reason under `## Documentation Impact` in `production/session-state/active.md`.
- Run `./codex-game-studio docs-impact --base <review-base>` and include its evidence in the handoff. Reviewers report unresolved documentation impact; writable implementation or fix work performs the update.
