Even more on difficulty
As one of the unique things about games as a medium, the discussion of challenge and punishment seems central to both the personally and commercially successful design, and to the academic view of what games really are. Veteran designer Brett Douville posted a bulleted list of how to manage difficulty in a fair way, his points are good but I find the main draw of the article is that he mentions challenging games as being exempt from providing an easy way out – perhaps an obvious point, but it is refreshing to see someone write a piece about challenge and recognize that there are games you play to experience and games you play to beat (be it the game or your own performance in it). Now, I prefer experiencing games myself but painting all games with the same brush is seldom a good idea and by consiously limiting the group of games he talks about Brett manages to provide more useful ways to work with them.
On a related note, Derek Yu has some interesting things to say about the achievement-reward balance, his questions and the ensuing comments brings a lot of new material to the discussion.