Game Theory class at Yale. Look here.

By end of class 1, here was the game:
“Without showing your neighbor what you’re doing, put in the box below a whole number between 1 and a 100 [whole number between 1 and 100–integer.] We will calculate the average number chosen in the class. The winner in this game is the person whose number is closest to two-thirds times the average in the class.” [Again: the winner is the person whose number is closest to two-thirds times the average number in the class.] The winner will win $5 minus the difference in pennies between her choice and that two-thirds of the average.”
Rules are:
(from the class transcript:)
“Before you go I want five things from you. I want to know the five lessons from this class. Tell me what you learnt? What were the five lessons? Without looking at your notes, what were the five lessons? Anybody, shout out one of the lessons, yes madam.
Student: Don’t play a strictly dominated strategy.
Professor Ben Polak: Don’t play a strictly dominated strategy, anything else? Yes sir.
Student: Yale students are evil.
Professor Ben Polak: Yale students are evil. Two lessons down, three to go. The guy over here.
Student: Rational choices can lead to bad outcomes.
Professor Ben Polak: Rational choices can lead to bad outcomes. We put it more graphically before but that’s fine. Two more outcomes.
Student: Put yourself in other people’s shoes.
Professor Ben Polak: Put yourself in other people’s shoes and I’m missing one, I can’t recall which one I’m missing now.
You could but it’s a good idea to figure out what you want before you try and get what you want.
The basic game plan:
1. Figure out a strategy that is going to bring you out on top
2. In this particular classroom, know that everyone else is coming from that position.
3. Rational choices can lead to bad outcomes (when everyone is being rational, it’s harder to win)
4. Think about what your opponent is thinking, knowing he/she is rational, too.
5. Figure out what you want before you try to get what you want