"Although in relation to the foreknowledge and decree of God, the first cause, all things come to pass immutably and infallibly, yet, by the same providence, he ordereth them to fall out according to the nature of second causes, either necessarily, freely, or contingently."

If we can speak of real contingency of second causes, then does that mean chance really does exist (from the perspective of second causes)? Wouldn't it exist in the same way free will does? If chance does exist so, why the problem with saying things like "Good luck" or "You were lucky/unlucky" etc.?