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 unreal-behavior-treesgit 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/unreal-behavior-trees)<a href="https://agentmods.dev/skills/gamedev-skills/awesome-gamedev-agent-skills/unreal-behavior-trees"><img src="https://agentmods.dev/badge/skills/gamedev-skills/awesome-gamedev-agent-skills/unreal-behavior-trees/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/unreal-behavior-trees"><img src="https://agentmods.dev/badge/skills/gamedev-skills/awesome-gamedev-agent-skills/unreal-behavior-trees.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector pass
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 | $0.00087 | $0.01428 |
| Opus 5 | $0.00044 | $0.00714 |
| Sonnet 5 | $0.00017 | $0.00286 |
| Haiku 4.5 | $0.00009 | $0.00143 |
Grade A, and why
unreal-behavior-trees 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 12d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- unreal-behavior-trees — 91% identical, 8 lines differ
How it starts
The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Unreal Behavior Trees
Author NPC decision-making in UE5 with Behavior Trees driven by a Blackboard: structure the tree with composites, gate branches with decorators, keep state current with services, and run it from an AIController. Targets UE 5.8.
When to use
- Use when building enemy/NPC AI: creating a
BT_/BB_asset pair, structuring Selector/Sequence branches, adding decorators (conditions) and services (periodic updates), writing customBTTask/BTServicenodes, or wiring an AIController to run the tree. - Use when the project has Behavior Tree (
BT_) and Blackboard (BB_) assets and anAAIController.
When not to use: the concept of AI (FSM vs BT vs steering, cross-engine) →
game-ai. Pure navigation/pathing math is engine navmesh (BT's MoveTo uses it). Simple
one-off logic may be cheaper as a small state machine than a full tree.
Core workflow
- Create the pair: a Blackboard (
BB_) holds typed keys (the AI's memory:TargetActor,LastKnownLocation,bIsInvestigating); a Behavior Tree (BT_) references that Blackboard. - Possess and run. An
AAIControllerpossesses the pawn and callsRunBehaviorTree(BT), which also initializes the referenced Blackboard. - Structure with composites. Selector runs children left→right until one succeeds (priority/fallback: "attack, else chase, else patrol"). Sequence runs children until one fails (do-all: "move to cover → reload → peek"). Simple Parallel runs one main task alongside a secondary.
- Gate branches with Decorators that read Blackboard keys (e.g. "Has Target?" guards the combat branch). Set Observer Aborts so the tree re-evaluates when the key changes.
- Keep the Blackboard current with Services attached to a branch — they tick periodically
(e.g. update
TargetActorvia a sight check) only while that branch is active. - Do work in Tasks, which return
Succeeded,Failed, orInProgress(latent tasks likeMoveTofinish later). - Verify with the Behavior Tree debugger during PIE — it highlights the running node and shows live Blackboard values, so you see exactly which branch executes.
What ships with it
1 file 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.
- 12d ago First seen · 115 lines · 87 tokens per session scan A 0c8ca83b7edb
unreal-behavior-trees 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 87 tokens to every session and 1,428 once invoked, about $0.0004 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 2026-08-30.
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.