Having a Issue with NPC Attack Script, Recv is high ingame?

I understand what I'm doing wrong and why it's high in Recv but I don't know how to get around this issue or how to fix it. There is around 20 NPC's on the map with this Script.

--EDIT-- The Script Checks if the player is within Range and Attacks the player and put's a Sound of the NPC hitting them but this Checks all the time and it's making the game lag when there's a lot of NPC's. The Line of code that I figure out that was making this issue is this..

local Players = game.Players:GetPlayers() for i,Player in ipairs (Players) do local char = Player.Character local Plr = Player if char ~= nil then local hum = char:FindFirstChild("Humanoid") if char.UpperTorso ~= nil then local Plu = char.UpperTorso

With this it's checking all Players ingame all the time and Rising the Recv end to 100-1000ms, This is what I'm trying to get help with, I like to know if there's a diff way to go around using that so I can check if the player is within Range or not but not have it run a 100 times within a second. There's no errors with the script.

`local NPC = script.Parent.Parent local Humanoid = NPC:WaitForChild('Zombie') repeat wait() until script.Parent.Parent.Torso local Damage = game.ReplicatedStorage.BoarConfigs.BoarDamage.Value

local COOLDOWN = 3 local h = false

while wait() do

local Players = game.Players:GetPlayers()
for i,Player in ipairs (Players) do
	local char = Player.Character
	local Plr = Player
	if char ~= nil then
	local hum = char:FindFirstChild("Humanoid")
	if char.UpperTorso ~= nil then
		local Plu = char.UpperTorso
		local m = (script.Parent.Parent.HumanoidRootPart.Position - Plu.Position).magnitude
		if m <=6 then
		if h == false and hum.Health >0 then
		if Plu ~= nil then	
	local Def = char.Def
	local SDef = char.SDef
	local MainDef = Def.Value + SDef.Value
	local NewDamage = Damage - MainDef
	
	local asound = Instance.new("Sound", char.Head)
		asound.SoundId = "http://www.roblox.com/asset/?id=367499850"
		asound.Name = "MobAttack"
		asound.Volume = 0.3
		asound.PlaybackSpeed = 0.3
		asound:Play()
		hum.Health = hum.Health - NewDamage
		Humanoid.WalkSpeed = 13
		h = true
		wait(COOLDOWN)
		char.Head.MobAttack:Destroy()
		Humanoid.WalkSpeed = 16
		h = false
	else
		print("Player has left the game or isn't in Range")
		end
		end
end
end
	end
	end
end`

If anyone can give me a hint on a way around this or let me know how too would be great.