Global 'up', 'Uro' is only used in the enclosing function 'Explode'; consider changing it to local?

local Rep = game:WaitForChild("ReplicatedStorage") local remote = Rep:WaitForChild("explode")

remote.OnServerEvent:Connect(function(player) local character = player.Character local RootPart = character:WaitForChild("HumanoidRootPart") local folder = workspace:FindFirstChild("DebrisFolder") or Instance.new("Folder",workspace) folder.Name = "DebrisFolder"

local position = Instance.new("BodyVelocity",RootPart)
position.MaxForce = Vector3.new(9999999999999, 9999999999999, 9999999999999)
position.P = 300
position.Velocity = RootPart.CFrame.LookVector * .1
game.Debris:AddItem(position,2)

local val = -4
local sizez = 3
local sizex = 10
local sideval = .5




local function Explode()
	local extra = math.random(-11,11)/10
	local fire = game.ReplicatedStorage:WaitForChild("Explosion"):Clone()
	local side = math.random(-sideval,sideval)
	up = fire.Size.Y/2
	local rotate = math.random(0,180)
	
	local MRo = math.random(99,100)
	if MRo == 99 then
		local SRo = math.random(8,10)/10
		URo = MRo + SRo	
	else
		local SRo = math.random(1,3)/10
		URo = MRo + SRo	
	end
	
	fire.Size = Vector3.new(sizez,sizex,sizez)
	fire.CFrame = RootPart.CFrame * CFrame.new(side,-up,val + extra)
	fire.Parent = folder
	fire.CFrame = fire.CFrame * CFrame.fromEulerAnglesXYZ(side,-up, val + extra)
	
	
	val = val - 2
	sizez = sizez + 1
	sizex = sizex + 1
	sideval = sideval + .5
	game.Debris:AddItem(fire,5)
	
	
	spawn(function()
		wait(.5)
		local tween = game:GetService("TweenService")
		
		local info = TweenInfo.new(
			.3,
			Enum.EasingStyle.Sine,
			Enum.EasingDirection.Out,
			0,
			false,
			0
		    )
		
		local properties = {
			CFrame = fire.CFrame * CFrame.new(0,up * 1.5, 0)
		    }
		
		local Tween = tween:Create(fire,info,properties)
		Tween:Play()
		
	end)
	
	
	
	
	
	
	
	
	
	
end

for i = 1,50 do
	Explode()
	wait()
	
	
end

end)

on the top of your script add

local uro = nil
local up = nil