Can't believe no one has the answer to this so I thought I'd throw my 2 cents in.
On Royal Caribbean, there was no charge to play pool but you had to leave your SeaPass w/ the bartender when you get the balls. That was their way of insuring that you bring the balls back.
Also no charge to play darts.
I suspect NCL is the same.
Can't help you with foosball but if it is located in the arcade then I would bet there is a charge to play just like any other arcade.
I know this doesn't quite answer your question but it should send you in the general direction.