version: "1.0.1" name: roblox-npc-ai description: "Use when creating or fixing Roblox NPCs, bots or enemies: pathfinding, state machines, line of sight, spawns, AI update loops." when_to_use: "Also when NPCs get stuck, walk through walls, chase wrongly, lag the server, or bots need to fill empty servers." last_reviewed: 2026-10-14 sources:

• https://raw.githubusercontent.com/Roblox/creator-docs/main/content/en-us/characters/pathfinding.md
• https://create.roblox.com/docs/projects/server-authority
• original

Roblox NPC & AI

When to Load

Load for NPCs/enemies: pathfinding, state machines, LOS/FOV detection, spawns, AI loops, or physics ownership.

Quick Reference

PathfindingService

local path = PathfindingService:CreatePath({
    AgentRadius = 2, AgentHeight = 5, AgentCanJump = true,
    Costs = { Water = 20, DangerZone = math.huge },
})
path:ComputeAsync(npcPos, targetPos)
if path.Status ~= Enum.PathStatus.Success then return end
for _, wp in path:GetWaypoints() do
    if wp.Action == Enum.PathWaypointAction.Jump then humanoid.Jump = true end
    humanoid:MoveTo(wp.Position)
    if not humanoid.MoveToFinished:Wait() then return end
end

• Recompute on blocked with a bounded retry or cancellation policy.
• In Studio, test Workspace.PathfindingUseImprovedSearch on representative maps before rollout; it is not scriptable.
• Avoid long requests and repeated recomputation. Moving collidable geometry can trigger navigation-mesh work.
• Region modifiers: anchored part + PathfindingModifier Label → Costs
• PassThrough = true for doors; PathfindingLink for disconnected navmesh
• math.huge cost = non-traversable

State Machine

idle → patrol → chase → attack → flee → dead

• idle/patrol → chase (player detected) → attack (in range) → idle (lost)
• any → flee (health low) → idle (safe); any → dead (health ≤ 0)
• Transitions own movement changes, target cleanup, and cancellation

Detection (distance → FOV → LOS)

1. Distance (a-b).Magnitude: cheapest, always first
2. FOV forward:Dot(toTarget) cosine; use a configured cone for your game, not a universal angle
3. LOS workspace:Raycast: expensive, last

• If the design includes hearing or proximity detection, make it a separate configured signal rather than a universal FOV bypass.

Network Ownership

• Classic projects may use SetNetworkOwner(nil) for physics-sensitive NPCs, but it is not complete security. In Server Authority projects, configure the authority model instead of treating network ownership as the security boundary.

Update Loop

• Throttle and stagger AI based on NPC count, path cost, and profiler evidence, not a universal tick rate. Keep NPC decisions and movement server-side; client code may handle presentation.

For spawners, lifecycle cleanup, timeout handling, and performance budgets, load references/full.md.