How Can I fix My RNG Dropping system?

This is my code, line 13, or " local ChosenNumber = math.Random(0,10)" errors, attempted to call nil value. I'm not sure how to fix this because I have never used math.random, have a misplaced a character? (and yes this is in a respawning script)

Dummy = script.Parent.Parent.Dummy
Clone = Dummy:Clone()

function Regen()
wait(3)
Dummy.Parent = nil
Clone.Parent = script.Parent.Parent
Dummy = Clone
Dummy:makeJoints()
Dummy.Torso.CFrame = script.Parent.CFrame + Vector3.new(0,2.7,0)
    Clone = Dummy:Clone()

    local ChosenNumber = math.Random(0,10)

    if ChosenNumber == 10 then

        local clonedsword = game.ReplicatedStorage.Library["Steel Greatsword"]:Clone()
        clonedsword.Parent = game.Players.LocalPlayer.Backpack
    end

    Dummy.Humanoid.Died:connect(Regen)
end

Dummy.Humanoid.Died:connect(Regen)