A house rule can make an old game feel like part of a family.

Every household that plays a game for long enough starts bending it. Someone decided years ago that you collect the fines in the middle, or that the first turn goes to whoever is youngest, and now that is simply how it is done here. The rule itself is unimportant; what matters is that it came from your people and exists nowhere else. A mass-produced box becomes particular through the amendments made to it.

Notice which of your rules are actually printed and which you invented, and tell a newcomer the story of one of them. Inviting somebody into a household custom is a quicker welcome than explaining the official instructions.