game-ai

Q: How do I install game-ai?

Run npx skills add https://github.com/gamedev-skills/awesome-gamedev-agent-skills --skill game-ai in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/game-ai/ (personal) or .claude/skills/game-ai/ (project).

by gamedev-skillsMedia & Creative

Design NPC and enemy decision-making with finite state machines, behavior trees, steering behaviors, and A pathfinding — engine-neutral algorithms that pair with the detected engine's navigation API. Use when building enemy AI, an FSM or behavior tree, steering/flocking, or pathfinding, or when the user mentions state machine, behavior tree, blackboard, A, navmesh, seek, or patrol/chase.

Installs: 7.8K
Last 24h: +372
Trending rank: #839
Security: Pass

Install

Works with every agent the skills CLI supports.

npx skills add https://github.com/gamedev-skills/awesome-gamedev-agent-skills --skill game-ai

01
Install
Run the command in your project. The CLI asks which agents to install for.
02
Describe the task
Ask your agent for something this skill covers. It loads game-ai automatically when relevant.
03
Review the result
The agent follows the SKILL.md steps, scripts and references bundled with the skill.

Security audits

Independent scans of the skill's instructions and bundled files.

Gen Agent Trust Hub PassSAFE ·This skill provides educational content and implementation templates for common game AI algorithms including state machines, behavior trees, and pathfinding. No security risks or malicious patterns were identified.

Socket PassNo alerts

Snyk PassLOW ·Risk: LOW · No issues

SKILL.md

The instructions your agent reads when the skill is triggered.

Game AI: decisions, steering, and pathfinding

Build believable NPC behavior from three separable layers: decide (what to do), steer (how to move there), and path (how to route around the map). Keep them decoupled — a behavior tree picks a target, the pathfinder produces waypoints, steering follows them. This skill teaches the engine-neutral algorithms; bind them to your engine via the related skills below.

When to use

Use when implementing enemy/NPC logic: patrols, chase/flee, guard states, group movement, or "find a path to the player".
Use to choose between an FSM (few clear states), a behavior tree (many reactive behaviors with priorities), or steering (smooth local movement).
Use when integrating pathfinding: A* on a grid/graph, or driving an engine navmesh agent.

When not to use: for the engine's concrete navmesh/agent API and baking, use unity-navmesh, unreal-behavior-trees, or Godot's NavigationAgent2D/3D (see that engine skill). For movement/collision feel, use physics-tuning. For spawning waves along lanes, see the tower-defense genre skill.

Core workflow

Pick the decision model by complexity. 2–5 states with obvious transitions → FSM. Many behaviors, priorities, interruption, reuse → behavior tree. Continuous "how strongly do I want each option" → utility scoring.
Separate decision from motion. The decision layer outputs an intent (target position, action). Steering or pathfinding turns intent into motion.
Path on the right graph. Grid tiles, waypoint graph, or a baked navmesh. Fewer nodes = faster A*. Prefer the engine's navmesh for 3D; A* on a grid for tile games.
Steer along the path, not straight to the goal — follow the next waypoint, advancing when close, so agents round corners.
Recompute paths sparingly. Pathfind on a timer or when the goal moves a tile, not every frame. Cache the path; only the waypoint index advances.
Verify by observation. Watch the agent: does it reach the goal, get stuck on corners, oscillate between states? Draw the path and current state on screen while tuning.

Patterns

1. Finite state machine (one state object, explicit transitions)

# Godot 4.7, one class per file.
# state.gd: each state is a small object with enter/update/exit.
class_name State extends RefCounted
func enter(_agent) -> void: pass
func update(_agent, _dt: float) -> State: return null   # return a state to transition
func exit(_agent) -> void: pass

# chase.gd: returns Patrol when the player escapes sight range.
class_name Chase extends State
func update(agent, dt: float) -> State:
    if not agent.can_see(agent.target):
        return Patrol.new()                 # transition by returning the next state
    agent.move_toward(agent.target.position, dt)
    return null                             # null = stay in this state

# enemy.gd: the agent owns `current` and ticks it once per frame.
var current: State = Patrol.new()           # call current.enter(self) in _ready()

func tick(dt: float) -> void:
    var next := current.update(self, dt)
    if next != null:
        current.exit(self)
        next.enter(self)
        current = next

Keep transition logic inside states (or in a table), never as a growing pile of if flags. One state owns one behavior; that is what keeps an FSM readable.

2. Behavior tree tick (composite nodes return a status)

# A node's tick() returns SUCCESS, FAILURE, or RUNNING (still working this frame).
enum Status { SUCCESS, FAILURE, RUNNING }

# Sequence: run children in order; stop at the first non-SUCCESS (logical AND).
func sequence_tick(children, agent, dt) -> int:
    for child in children:
        var s = child.tick(agent, dt)
        if s != Status.SUCCESS:
            return s                 # FAILURE or RUNNING short-circuits the sequence
    return Status.SUCCESS

# Selector: try children until one succeeds or is RUNNING (logical OR / fallback).
func selector_tick(children, agent, dt) -> int:
    for child in children:
        var s = child.tick(agent, dt)
        if s != Status.FAILURE:
            return s                 # SUCCESS or RUNNING stops the search
    return Status.FAILURE

A guard AI reads top-down: Selector[ Sequence[CanSeePlayer?, Chase], Patrol ] — chase if visible, otherwise patrol. See references/behavior-trees.md for leaf nodes, decorators (Inverter, Cooldown), and a blackboard.

3. Steering: seek and arrive (smooth, frame-rate independent)

# Seek: accelerate toward a target at full speed. Steering = desired - current.
func seek(pos, vel, target, max_speed, max_force) -> Vector2:
    var desired = (target - pos).normalized() * max_speed
    return (desired - vel).limit_length(max_force)   # a force, not a teleport

# Arrive: like seek, but ramp speed down inside slow_radius so it stops cleanly.
func arrive(pos, vel, target, max_speed, max_force, slow_radius) -> Vector2:
    var offset = target - pos
    var dist = offset.length()
    if dist < 0.001: return (-vel).limit_length(max_force)   # already there: brake
    var ramped = max_speed * min(dist / slow_radius, 1.0)
    var desired = offset / dist * ramped
    return (desired - vel).limit_length(max_force)

# Per frame: vel += steering * dt; pos += vel * dt   (always scale by dt)

4. A* heuristic must not overestimate (or paths stop being shortest)

# Match the heuristic to the movement. An ADMISSIBLE heuristic (never larger
# than the true remaining cost) keeps A* optimal.
def heuristic(a, b):                 # a, b are (x, y) grid cells
    dx, dy = abs(a[0] - b[0]), abs(a[1] - b[1])
    # return dx + dy             # Manhattan: 4-direction grids (no diagonals)
    return (dx + dy) + (1.414 - 2) * min(dx, dy)   # octile: 8-direction grids
# f(n) = g(n) + h(n): g = cost from start, h = heuristic to goal.
# Overestimating h is faster but no longer guarantees the shortest path.

The full A* loop (priority queue, came_from reconstruction, grid + waypoint graphs) is in references/pathfinding.md.

Pitfalls

Pathfinding every frame tanks the frame rate. Recompute on a timer or only when the target moves to a new tile; follow the cached waypoints in between.
Steering straight to the goal instead of to the next waypoint makes agents hug walls and corners. Follow the path; advance the waypoint when within radius.
Inadmissible A* heuristic (e.g. Euclidean distance scaled up, or Manhattan on a diagonal grid) returns fast but non-shortest paths. Pick the heuristic that matches your allowed moves.
Behavior tree leaves that never return RUNNING for multi-frame actions (walking, playing an animation) cause the tree to restart the action every tick. Return RUNNING until the action completes.
FSM transition spaghetti: scattering if state == ... checks everywhere recreates the mess an FSM exists to prevent. Keep transitions in the state.
No line-of-sight or stuck check → agents grind into walls forever. Add a timeout that forces a repath or a state change.

References

references/pathfinding.md — complete A* (priority queue, reconstruction), grid vs waypoint graphs, when to defer to an engine navmesh.
references/behavior-trees.md — node taxonomy, leaf/decorator implementations, blackboard, and FSM-vs-BT selection.

Related skills

ai-behavior-trees-utility-ai — deeper behavior-tree and utility-AI design.
unity-navmesh, unreal-behavior-trees — concrete engine AI/navigation APIs.
physics-tuning — movement, collision response, and agent radius.
procedural-gen — generating the graph/level the AI navigates.
tower-defense, fps-shooter — genres that compose this skill.

FAQ

What does the game-ai skill do?

How do I install game-ai?

Run npx skills add https://github.com/gamedev-skills/awesome-gamedev-agent-skills --skill game-ai in your project. The skills CLI detects the agents you use and copies the skill into the right folder. For Claude Code you can also place the skill folder at ~/.claude/skills/game-ai/ (personal) or .claude/skills/game-ai/ (project).

Which AI agents can use game-ai?

Any agent that supports the open Agent Skills format (a folder with a SKILL.md file), including Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, Windsurf, Cline, OpenCode and more.

Is game-ai safe to install?

Security partners have reviewed it: Gen Agent Trust Hub passed; Socket passed; Snyk passed. As with any skill, read the SKILL.md and bundled scripts before installing.

Who maintains game-ai?

It is published by gamedev-skills in gamedev-skills/awesome-gamedev-agent-skills. It has 7,808 recorded installs.