Sword damage script not working in a real game?

local tool = script.Parent
local handle = tool:WaitForChild("Handle")
local flesh = handle:WaitForChild("Hit")
local blade = tool:WaitForChild("Blade")
local detect = tool:WaitForChild("CanAttack")

blade.Touched:connect(function(hit)
    if detect.Value == true then
        local hum = hit.Parent:FindFirstChild("NPC")
        if hum then
--[[        
            for i,v in pairs(hit.Parent:GetChildren()) do
                if v:IsA("IntValue") then
                    v:Destroy()
                end
            end
            local kill = Instance.new("IntValue",hit.Parent)
            kill.Name = script.Parent.Parent.Name
--]]
            detect.Value = false
            flesh:Play()
            hum:TakeDamage(4)
            wait(1)
            detect.Value = true
        end
    end
end)

When the blade of the sword (a part) hits a NPC, it will check for the NPC's humanoid which is named "NPC" so that players can't kill each other. If it finds it, it will do damage to the NPC. The script works in studio but not in a real game with no errors.