We made a mistake in our initial design. We wanted the rulebook to be as clear and easy on the eyes as possible so we tried to maximize the size of the rulebook. However, we realized that the rulebook can't fit in the piano box (unless you roll it up :D).This is our mistake and we will adjust the design in future batches. It shouldn't affect your experience much as the card descriptions are quite self-explanatory. We've uploaded the rulebook and specific questions here (TBD) on our website for any quick access you need during a game!