Adam Saltsman @ Gamasutra: "A much more well-known designer wrote a nice article about Dynamic Difficulty Adjustment (DDA) right here on Gamasutra about a year ago. It's a nice article, concluding:
"Don't let your players find out exactly what performance-evaluation mechanism you're using, nor what the game will do to make things easier. Without this knowledge the players can't exploit the system so easily."
I think this makes a nice jumping-off point for my musings on these systems today, particularly because the second best system I am going to talk about actually goes to great lengths to make it excessively clear what mechanism it is using, and it works far better than the best hidden systems. The most elegant system I'm going to present doesn't even have an algorithm, which is pretty nuts. That's not to say this designer was wrong by any means, just that this is definitely a weird and broad topic.
I'm going to cover maybe four different systems here, and they will be presented in order from most artificial, frustrating, and complex up to one system that I think is extraordinarily elegant and simple. I think these are my first case studies or direct references to actual games on the blog, and I realize this invites a certain amount of argument and dissension, but hey, what is practical analysis without a few suitable examples?"