I was somewhat disappointed to find a lack of Magic: the Gathering players on LessWrong when I asked about it in the off-topic thread. You see, competitive Magic is one of the best, most demanding rationality battlefields that I know about. Furthermore, Magic is discussed extensively on the Internet, and many articles in which people try to explain how to become a better Magic player are, essentially, describing how to become more rational: how to better learn from experience, make judgments from noisy data, and (yes) overcome biases that interfere with one's ability to make better decisions.
Because people here don't play Magic, I can't simply link to those articles and say, "Here. Go read." I have to put everything into context, because Magic jargon has become its own language, distinct from English. Think I'm kidding? I was able to follow match coverage written in French using nothing but my knowledge of Magic-ese and what I remembered from my high school Spanish classes. Instead of simply linking, in order to give you the full effect, I'd have to undertake a project equivalent to translating a work in a foreign language.
So it is with great trepidation that I give you, untranslated, one of the "classics" of Magic literature.
Stuck In The Middle With Bruce by John F. Rizzo.
Now, John "Friggin'" Rizzo isn't one of the great Magic players. Far from it. He is, however, one of the great Magic writers, to the extent that the adjective "great" can be applied to someone who writes about Magic. His bizarre stream-of-consciousness writing style, personal stories, and strongly held opinions have made him a legend in the Magic community. "Stuck in the Middle with Bruce" is his most famous work, as incomprehensible as it may be to those who don't speak our language (and even to those that do).
So, why am I choosing to direct you to this particular piece of writing? Well, although Rizzo doesn't know much about winning, he knows an awful lot about what causes people to lose, and that's the topic of this particular piece - people's need to lose.
Does Bruce whisper into your ear, too?
I agree card games can be a decent training mechanism, but I think the efficacy increases with the games complexity. I played MTG in my youth and a number of other card games like L5R. In actuality I think MTG is one of the least complex card games in the market, lending to its wide popularity. Certainly it could be argued to be more complex in some ways then poker, but less then other games. At some point complexity makes a game overly convoluted or turns off more casual players if it reduces the ability for an average person to understand its basic facets (one advantage of games like chess/go is easily understandable basic rules, yet very complex and worthwhile strategical depth).
I tend to think any game can be construed as a means to train your thinking/brain, and in this case more specifically rationality, depending on the content. I also think things with a time metric allow more complex decision making due to the inherent time/thinking management issues. However, depending on the specific details of how our brain functions with respect to solving problems in specific games, it's hard to say what exactly is being improved unless tested.
An interesting fact is that I use to be an extremely competitive starcraft player, and some of the skills used in this game have a good correlate with games such as poker. A number of my fellow professional starcraft players moved on to poker where they now play for a living.
Which card game thus far encountered is the best rationality training mechanism, in your opinion?