Skills

What Are Skills?

Skills are best-practice guides that make AI agents better at game development. Each skill is a Markdown file (a SKILL.md) that teaches the agent a specific discipline: how to compose a scene, build an FPS controller, generate a character model, set up multiplayer, or debug a crash. When the situation matches, the agent loads the skill and follows it. The library ships with the Summer CLI and covers 20 categories spanning the whole game-dev workflow. Skills follow the Agent Skills open standard, so they work with Claude Code, Cursor, Codex, Gemini CLI, GitHub Copilot, OpenCode, and other compatible agents.

Quick Start

The recommended skill set installs automatically when you onboard an agent:

npx -y summer-engine@latest setup claude-code --yes

Or manage skills directly:

# List available skills
summer skills list

# Install the recommended set for an agent
summer skills install --recommended --agent claude-code

# Install one skill
summer skills install fps-controller --agent cursor

# Install every skill
summer skills install --all --agent claude-code

# Preview a skill
summer skills info debug

Categories

The library is organized into 20 categories. Recommended skills install by default; the rest are available on demand.

Workflow

Process disciplines that shape how the agent approaches a task before it touches code.

Skill	Use when
brainstorming	Starting a new game, mechanic, or feature; exploring intent and scope first
investigating-bugs	A first fix did not stick and you need root-cause analysis
verification-before-completion	About to claim a feature is done; forces a real check first
playtesting-a-feature	A gameplay feature is finished and needs a golden-path and edge-case playthrough
writing-plans	A multi-step spec needs a written plan with checkpoints
dispatching-parallel-agents	Two or more independent tasks can run in parallel
writing-skills	Authoring a new Summer skill
debugging-game-feel	Tuning feel (“the jump feels floaty”) one variable at a time
diagnosing-perf-regressions	FPS dropped after a change and you need to bisect the cause

Scene and Project

Skill	Use when
make-game	Building a narrow playable prototype from requirements end to end
brainstorm-game	Turning “I want to make a game” into a one-page brief at `.summer/GameSoul.md`
new-project	Starting a blank project (picks empty vs 3d-basic, opens the engine)
browse-templates	Choosing a community template to start from
scene-composition	Building scenes, organizing nodes, creating reusable prefabs
play	Running the game from a clean state and reporting whether it runs cleanly

Scripting Patterns

Skill	Use when
gdscript-patterns	Writing GDScript: type hints, signals, exports, lifecycle methods

Character Controllers

Skill	Use when
fps-controller	Building a first-person CharacterBody3D with movement, camera, and input

Gameplay Mechanics

Skill	Use when
design-mechanic	Designing a mechanic end to end: input, response, feedback, depth

Level Design

Skill	Use when
design-level	Designing a level as a paced encounter, then producing a node-tree skeleton

Rendering and Lighting

Skill	Use when
3d-lighting	Setting up sun, fill, WorldEnvironment, sky, and shadows
art-direction	Defining art direction and writing the art bible to `.summer/art-bible.md`

UI and UX

Skill	Use when
ui-basics	Building menus, HUDs, health bars, and responsive layout

Asset Pipeline

Skill	Use when
asset-strategy	Choosing between library, generated, or primitive assets for a level

2D Assets

Skill	Use when
concept-art	Producing variant concept-art prompts on a locked style anchor
character-portrait	A final character bust for dialogue UI
pixel-art	Pixel-art icons and sprites with nearest-neighbor filtering
ui-graphics	Flat-design UI icon sets and atlases
tileable-texture	Seamless textures for materials
sprite-sheet	Multi-frame sprite animations and SpriteFrames resources
skybox-panorama	Equirectangular skybox panoramas

3D Assets

Skill	Use when
prop-model	A single prop via the image-to-3D pipeline
character-model	A character: T-pose reference, gated rig pass, CharacterBody3D wiring
environment-kit	A modular kit of consistent environment pieces
vehicle-model	Hard-surface vehicles
organic-model	Organic shapes with emission and instancing

Animation

Skill	Use when
generate-motion	Adding a curated mocap clip to a rigged character
retarget	Retargeting an existing clip onto a different skeleton
animation-tree	Building an AnimationTree with blend spaces driven by speed
procedural-animation	Foot IK and other procedural skeleton modifications
facial-and-lipsync	Lip-sync and blend-shape facial animation from a voice line

Audio

Skill	Use when
audio-direction	Defining audio direction and the bus layout in `.summer/audio-bible.md`
sound-effect	A single SFX wired to an AudioStreamPlayer3D
music-track	A looping music track on the Music bus
ambient-bed	Loop-clean ambience on the Ambient bus
voice-line	Character dialogue via TTS with a matching voice
adaptive-music	Layered music that responds to combat state

Video

Skill	Use when
cinematic-cutscene	A short cutscene wired to a VideoStreamPlayer
trailer-shot	A premium hero shot for a trailer
animated-loop	A loop-clean backdrop clip for a title screen

Visual Effects

Skill	Use when
game-feel	Adding visible juice to flat combat: hit flash, screen shake, particles
fire	A torch flame via GPUParticles3D and a custom shader
muzzle-flash	A one-shot muzzle flash on a weapon
water-ripple	Interactive water ripples
lightning	A lightning strike effect with camera shake
dissolve	A dissolve-on-death shader effect
smoke	Smoke particles with wind
hit-spark	Sparks oriented to a surface normal on impact
magic-glow	A pulsing magical glow with light and motes

AI and NPCs

Skill	Use when
design-npc	A patrol-and-chase enemy with perception, decision logic, and tells

Multiplayer and Networking

Skill	Use when
setup-multiplayer	Co-op LAN multiplayer with MultiplayerAPI, Spawner, Synchronizer, and ENet
peer-to-peer-multiplayer	A four-layer P2P architecture with prediction and interpolation
host-authoritative-state	A state-ownership audit and the canonical Manager pattern

Performance

Skill	Use when
tune-performance	Profiling a slow scene, finding the hotspot, and verifying the fix moved the metric

Debugging

Skill	Use when
debug	Triaging a runtime crash end to end: read errors, locate code, fix, verify

Deployment

Skill	Use when
export-and-ship	Running the Steam pre-flight checklist across Windows, Mac, and Linux

For AI Agents

Most agents discover skills automatically once summer setup <agent> --yes has installed them. The agent loads the relevant SKILL.md when the situation matches, then follows its scene structure, value formats, and tool calls. Skills reference the MCP tools (summer_add_node, summer_set_prop, summer_generate_3d, etc.) and engine value formats (Vector3(0, 10, 0), Color(1, 0.5, 0, 1)).

Next Steps

CLI Reference

All CLI commands including skills

Building a Game

Step-by-step MCP workflow for AI agents

Need help or have questions? Reach out to our founders at founders@summerengine.com or join our community on Discord for fast responses.

Overview

Setup

CLI

Reference

What Are Skills?

Quick Start

Categories

Workflow

Scene and Project

Scripting Patterns

Character Controllers

Gameplay Mechanics

Level Design

Rendering and Lighting

UI and UX

Asset Pipeline

2D Assets

3D Assets

Animation

Audio

Video

Visual Effects

AI and NPCs

Multiplayer and Networking

Performance

Debugging

Deployment

For AI Agents

Next Steps

CLI Reference

Building a Game

​What Are Skills?

​Quick Start

​Categories

​Workflow

​Scene and Project

​Scripting Patterns

​Character Controllers

​Gameplay Mechanics

​Level Design

​Rendering and Lighting

​UI and UX

​Asset Pipeline

​2D Assets

​3D Assets

​Animation

​Audio

​Video

​Visual Effects

​AI and NPCs

​Multiplayer and Networking

​Performance

​Debugging

​Deployment

​For AI Agents

​Next Steps

CLI Reference

Building a Game

What Are Skills?

Quick Start

Categories

Workflow

Scene and Project

Scripting Patterns

Character Controllers

Gameplay Mechanics

Level Design

Rendering and Lighting

UI and UX

Asset Pipeline

2D Assets

3D Assets

Animation

Audio

Video

Visual Effects

AI and NPCs

Multiplayer and Networking

Performance

Debugging

Deployment

For AI Agents

Next Steps