The 2nd ever prisoner’s dilemma tournament that happens entirely on Facebook.

Buster Benson
Jul 21, 2018 · 4 min read

The first prisoner’s dilemma tournament last week was so much fun, so we’re gonna do another, with more teams this time! To watch or play, join this FB group.

A prisoner’s dilemma strategy is a description of logic about when to cooperate and when to defect, based on how other people cooperate with or defect against you. “Tit for tat” is a popular strategy that starts by cooperating and then copies the last move from the other player. It’s the strategy of “perfect fairness”. Other strategies are nicer, or meaner, and to better/worse against different kinds of strategies. A strategy can feel a lot like a worldview… that’s why this game gets so interesting! This link has a bunch of strategies, starting simple and getting sorta fancy.

Some famous strategies, left here without explanation:

Here’s how the 1st tournament worked:

  • 2 teams: To play, you joined one of 2 teams (Ant or Beetle) and picked a strategy to play against every person on the other team. You could talk to your team to get ideas and try to coordinate strategies. Let’s say you eventually picked “complete randomness” as a strategy — that means you’d cooperate 50% of the time and defect 50% of the time.

Tournament 2!

We learned some interesting things during this trial tournament, and are gonna tweak a few rules to make it even more interesting.

  • More teams: We’re gonna allow more than 2 teams (3–5, I think). This will make it so you can’t extort (or be extorted) entirely by another team because you don’t have to rely on them for all your team’s points. Other dynamics/conflicts of interest will emerge I’m sure.

Want to learn more and possibly play in the next tournament?

Team registration starts Sunday, July 22nd, and the games will start early August! Whether you want to play or just watch, join this Facebook Group.

If you want a quick primer on why prisoner’s dilemma is so interesting as a tool for understanding how cooperation evolved, this is one of the better intros:

🎟 Register for the tournament before July 29th! https://facebook.com/groups/dilemma

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