101 Closed System Scores and ranks have been used in arcade and single player games from the early days on.
Players itch to compare their performance, and they want to know where their peers and equals are.
Let's settle this once and for all. In its minimal form it implies that your actions will have some effect on the outcome. The elusive quality we call fun originates from the confidence that you can, and might have, won the game - that your actions can indeed affect the chain of game events, maybe enough to let you come out on top. You don't have to win to enjoy the game, but you expect a fighting chance. In his Glory and Shame , Jonathan Baron describes competitive multiplayer reality, and postulates that public humiliation drives away the casual gamer.