What problem does it solve? When writing code for s&box (Facepunch's Source 2 game engine with a C# scripting layer), AI assistants frequently hallucinate Unity patterns like void Start(), GetComponent<T>() call sites, Physics.Raycast, and [SerializeField] — none of which exist in s&box. This skill redirects code generation to the correct s&box APIs, with every signature verified against the engine's exported schema. ## Core Features & Use Cases - Router-based reference system: SKILL.md routes tasks to nine curated reference files covering core concepts, 144 built-in components, Razor UI, networking, input/physics, and full API schemas for ~790 types. - Unity-to-s&box translation table: Over 40 explicit mappings from wrong Unity patterns to correct s&box equivalents, plus ten mandatory rules (e.g., [Property] for serialization, [Sync] for networked state, Scene.Trace for raycasts). - Runnable examples: Ten complete schema-verified examples including a first-person controller, hitscan weapon, networked player with RPCs, Razor HUD, and NavMeshAgent AI. - Use Case: Ask how to write a networked player controller in s&box, and the skill loads the networking and patterns references to produce correct owner-authoritative code with [Sync] properties and IsProxy guards instead of Unity-style networking. ## Quick Start Ask the assistant to write an s&box component, such as a networked player controller or a Razor HUD panel, and it will consult the appropriate reference file before generating code.