"The "joy of discovery" is one of the fundamental joys of play itself. Not just the joy of discovering secrets within the game, but also the joy of uncovering the creator's vision. It's that "Aha!" moment where it all makes sense, and behind the world the player can feel the touch of another creative mind. In order for it to be truly joyful, however, it must remain hidden from plain view— not carved as commandments into stone tablets but revealed, piece by piece, through the player's exploration of the game's rules."