My fighting script isn't working?

local gui = game.Workspace.Part.v.z
local plrs = game.Players:GetPlayers()

function Intermission()
	for i = 20, 0, -1 do
		gui.Text = "Intermission: 0:"..i
		if i <= 9 then
			gui.Text = "Intermission: 0:0"..i
		end
		wait(1)
	end
end

function ChooseDuelers_Teleport()
	gui.Text = "Now choosing dulers, (1 and 2)."
	
	local p1 = plrs[math.random(1, #plrs)]
	local p2 = plrs[math.random(1, #plrs)]
	
	repeat local p2 = plrs[math.random(1, #plrs)]
	until p2 ~= p1
	
	gui.Text = p1.Name.. " and " ..p2.Name.. " have been chosen."
end

function Round()
	for i = 40, 0, -1 do
		gui.Text = "Round, please wait: 0:"..i
		if i <= 9 then
			gui.Text = "Round, please wait: 0:0"..i
		end
		wait(1)
	end
end

while true do
	if game.Players.NumPlayers > 1 then
		Intermission()
		ChooseDuelers_Teleport()
		Round()
	elseif game.Players.NumPlayers == 1 then
		gui.Text = "Waiting for 2 or more players."
	end
	wait()
end

ERROR: ServerScriptService.Script:17: bad argument #2 to 'random' (interval is empty)

Activate everything when there are 2 players or more in the game

Allow = false
game:GetService('Players').PlayerAdded:connect(function()
	--When a player is added, the value will update
	if game:GetService('Players'):GetPlayers() > 1 then
		Allow = true
	else
		Allow = false
	end
end)
game:GetService('Players').PlayerRemoving:connect(function()
	-- Same goes for last function
	if game:GetService('Players'):GetPlayers() > 1 then
		Allow = true
	else
		Allow = false
	end
end)
function example()
	--This is an example for every function
	if not Allow then return end
	--Code
end