Desigining a Legacy Game
Desigining a Legacy Game - Rob Daviau
"Risk Legacy was published in 2011 as a new way to play a board game -- one that remembers some events from game to game, that has secret components, that encourages writing on the materials, and ripping some up. SeaFall, due out in 2014, is another legacy game. Learn how to nearly go insane trying to design and test these, how randomness is your enemy but surprises are your friend, and why this isn't, and never will be, a "marketing gimmick"."
Risk Legacy is an incredible example of permanence in board games, you have stickers you place over rules in the rulebook and permanently on the board. Changing the game forever for who plays it next.