It's definitely possibly that two people can both have good luck in the same game.
And I don't think it's an empty formality if someone says "good luck" in every game. Just because something is done formally or routinely doesn't mean it is an empty gesture or meaningless.
Like in boxing matches, for example, at the start of every match the referees brings both pugilists to the center of the ring, explains the rules and tells them he wants a good, clean fight.
Is this necessary in a heavyweight championship fight? Don't the boxers know the rules? Couldn't we assume that the referee wants a good, clean fight without hearing him say it?
Yes to all questions.
However, rituals become meaningful and help bring pleasant order to our lives.
If someone says "good luck" to me, should I say "good luck" back? Surely it's a contradiction that we would both have good luck! And I wouldn't want to start a fight over it.
It's just a token. You're a cyborg from the future, aren't you dude?
There's a few of them floating around the place.
Someone has yet to explain the real value of this token. What is the point?