Roblox (Small AI PART/NPC)Script

--[[
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INSTRUCTION:
1.create Script inside part in workspace
2.put this code in script
3.run!
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SOCIAL/ADS:
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my YouTube channel:
https://www.youtube.com/channel/UC9mjJnPdd0aUqc_sHF2U_Tg
my profile on Roblox:
https://www.roblox.com/users/140427102/profile
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Enjoy guys!
--]]
-- Variables settings
local klocek = script.Parent -- change path of part in Workspace
local max_distance = 30 -- max distance of range part to see humanoid(player) object
local speed = 0.33 -- change it (what speed of functions are to be performed)
local speedPart = 12 -- speed of part
local DamagePart = 6 -- damage of part
local startedPosition = klocek.Position -- variable storage first position of part so we can returned the started postion later
local isAttacking = false -- if part attacking player so does not attack other opponents
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local function ReturnToStart()
    isAttacking = false
    local distanceToStart = (klocek.Position - startedPosition).Magnitude
    while distanceToStart >= 0.9 do
        distanceToStart = (klocek.Position - startedPosition).Magnitude
        klocek.CFrame = CFrame.new(klocek.Position,startedPosition)
        klocek.Velocity = klocek.CFrame.LookVector * speedPart
        wait(speed)
    end
end

-- this function search in workspace (model, humanoid and upperTorso) of players if not exists return nil
local function SearchPlayer()
    for _,v in pairs(workspace:GetChildren()) do
        if v and v:IsA("Model") and v:FindFirstChild("Humanoid") then
            if v.Humanoid.Health >= 1 then

                local torso = v:FindFirstChild("UpperTorso")
                local humanoid = v.Humanoid
                local Distance = (torso.Position - klocek.Position).Magnitude

                if Distance > max_distance then
                    continue
                end

                if torso then
                    isAttacking = true
                    return torso,humanoid
                else
                    -- if humanoid don't have torso we return nil
                    return nil
                end

            else
                -- if humanoid health have smaller health than 1 return nil
                return nil
            end
        end
    end
    -- if humanoid with model of player doesn't exists in workspace we return nil
    return nil
end

local function MovePart(part)
    local torso,humanoid = SearchPlayer()
    local distanceToStart = (klocek.Position - startedPosition).Magnitude

    if not torso and distanceToStart >= 0.9 then
        return ReturnToStart()
    end

    if torso then
        local Distance = (torso.Position - klocek.Position).Magnitude
        if Distance <= max_distance then

            klocek.CFrame = CFrame.new(klocek.Position,torso.Position)
            klocek.Velocity = klocek.CFrame.LookVector * speedPart

            if Distance <= 3.5 then
                humanoid.Health -= DamagePart
            end


        elseif Distance > max_distance and distanceToStart >= 0.9 then
            return ReturnToStart()
        end


    end
end

while true do
    MovePart(klocek)
    wait(speed)
end