--Put this in ServerScriptService--

game.Players.PlayerAdded:connect(function(Player)
	local Data = Instance.new("IntValue",Player)
	Data.Name = "Data"
	local XP = Instance.new("IntValue",Data)
	XP.Name = "XP"
	XP.Value = 0
	local Level = Instance.new("IntValue",Data)
	Level.Name = "Level"
	Level.Value = 1

	XP.Changed:connect(function() XPChange(Player,XP,Level) end)

end)

function XPChange(Player,XP,Level)
	if XP.Value >= Level.Value*150 then
		XP.Value = 0
		Level.Value = Level.Value + 1
		game.Players.LocalPlayer.Character.Humanoid.MaxHealth = game.Players.LocalPlayer.Character.Humanoid.MaxHealth + 50
	end
end