Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add gamedev-skills/awesome-gamedev-agent-skills --skill roblox-physicsgit clone --depth 1 https://github.com/gamedev-skills/awesome-gamedev-agent-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/gamedev-skills/awesome-gamedev-agent-skills/roblox-physics)<a href="https://agentmods.dev/skills/gamedev-skills/awesome-gamedev-agent-skills/roblox-physics"><img src="https://agentmods.dev/badge/skills/gamedev-skills/awesome-gamedev-agent-skills/roblox-physics/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/gamedev-skills/awesome-gamedev-agent-skills/roblox-physics"><img src="https://agentmods.dev/badge/skills/gamedev-skills/awesome-gamedev-agent-skills/roblox-physics.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00094 | $0.01702 |
| Opus 5 | $0.00047 | $0.00851 |
| Sonnet 5 | $0.00019 | $0.00340 |
| Haiku 4.5 | $0.00009 | $0.00170 |
Grade A, and why
roblox-physics scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Roblox physics
Choose deliberately between simulation, character control, hit detection, and visual-only motion;
they are different jobs. Targets Roblox's rolling platform APIs. Pair with physics-tuning for
engine-neutral stability and feel.
When to use
- Use for BasePart assemblies, constraints, collision/query policy, ray/overlap queries, forces, impulses, moving physical objects, network ownership, or physics cleanup.
- Use when
Touchedis unreliable/security-sensitive, parts tunnel or jitter, a mechanism breaks when anchored, or old BodyMover patterns appear.
When not to use: ordinary Humanoid lifecycle/control belongs to roblox-characters; remote
validation belongs to roblox-networking; decorative UI/world motion may only need a tween.
Decide the system first
| Goal | Mechanism |
|---|---|
| sustained physical interaction | unanchored assembly + modern constraints/forces |
| instantaneous physical change | ApplyImpulse / ApplyAngularImpulse |
| kinematic platform/path | controlled pivot/transform with an explicit passenger policy |
| character locomotion | Humanoid/custom character controller (roblox-characters) |
| authoritative hit test | server raycast/overlap with filters and gameplay validation |
| cosmetic trail/recoil | local visual motion; no gameplay authority |
Workflow
- Inspect the mechanism. In Studio, visualize assemblies, anchors, constraints, collision groups, massless parts, and network owners. Identify the assembly root and intended authority.
- Define interaction policy. Write the collision-group matrix and separately decide
CanCollide,CanTouch, andCanQuery. These flags are not interchangeable. - Choose simulation or query. Do not use
.Touchedas a universal hit detector. Use a ray for a path/line, an overlap query for a volume, and simulation contacts when physical response is actually required. - Apply motion at assembly level. Forces on a part affect its assembly. Use modern
LinearVelocity,AngularVelocity,VectorForce,AlignPosition, andAlignOrientationconstraints as appropriate; migrate deprecated BodyMovers when changing that system. - Set ownership deliberately. Server-own gameplay-critical loose assemblies when required; client ownership can improve responsiveness but never authorizes gameplay results.
- Bound cost and lifetime. Reuse query parameters, cap query frequency/result count, remove temporary constraints/attachments, and disconnect event listeners.
- Verify under load and multiplayer. Test anchored/unanchored transitions, mass extremes, collision matrix, fast motion, multiple clients, ownership changes, streaming, and cleanup.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 3d ago First seen · 152 lines · 94 tokens per session scan A b91d88793183
roblox-physics is a skill published in the GitHub repository gamedev-skills/awesome-gamedev-agent-skills (952 stars, last pushed 2d ago), licensed Apache-2.0. It adds 94 tokens to every session and 1,702 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-09.
Other skills, from other repositories
assets-get-data
Get asset data from the asset file in the Unity project — every serializable field and property. Supports token-saving path-scoped reads via paths or viewQuery. Use 'assets-find' to find the asset first.
gameobject-set-parent
Reparent a batch of GameObjects under a new parent in the currently opened Prefab or active Scene. Per-item failures are reported in the returned status string instead of aborting the batch. Use 'gameobject-find' to locate the GameObjects first.
unity-version-split
Split a C# file into Unity 6.5+ and pre-Unity 6.5 variants. Use when a file needs different implementations for different Unity versions due to API changes (e.g., EntityId vs int, GetEntityId vs GetInstanceID).
profiler-save-data
Save a snapshot of profiler-derived stats (status + memory + rendering + script + frame capture) to a JSON file. Built-in Unity APIs only.
assets-shader-list-all
List all shaders available in the project assets and packages, sorted by name. Use this to discover a valid shaderName for 'assets-material-create'.
profiler-stop
Disable Unity's runtime profiler. Idempotent — calling when already disabled returns the current disabled state.