Two partners in crime, two separate rooms, and one choice that could save or sink them both.
Experts from around the world wrote computer programs to compete in a famous strategy tournament. How long was the winning program?
Four lines of code Anatol Rapoport's entry, called tit for tat, was the simplest program submitted: cooperate first, then copy whatever your opponent did last.
One English university entered dozens of programs into a strategy contest. Why were many of them built to lose on purpose?
To help a teammate win Southampton's programs used a secret opening 'dance' of moves to recognize each other, and then one would always give in so its partner could rack up points.
When programs played each other again and again, which kind of strategy came out ahead: the greedy ones or the nice ones?
The nice ones Robert Axelrod found the winners were nice, quick to strike back, quick to forgive, and never jealous of their opponent's score.
Researchers built digital worlds where strategies competed for survival. What happened to the programs that scored poorly?
They died off In these simulations the high scorers reproduced with small random changes, and the population tended to fill up with tit for tat players.
This puzzle began as a math game at a think tank. What did a mathematician add that gave it its famous name?
Prison sentences Albert W. Tucker framed the rewards as jail time, and today the label is used for any situation where two sides would gain by cooperating but struggle to do it.
