In a pool with a sufficient number of close-to-mimicbots, considering use of language features you didn't anticipate or can't handle to be defections seems like a good way to get too many mutual defections to win.

Also, not sure what "mutation" means in context. If you mean "almost quine yourself, but write in a few differences", N did that; I can't think of any other reasonable meanings which N does. I used namespace-set-variable-value! merely so that eval could see my variables; in most lisps I've used in the past I could have omitted it entirely.

By mutation I mean set!, or anything else that can change the value of a variable; things ending in '!'. namespace-set-variable-value! does technically mutate things but looking at the way people actually used it I don't think it would have caused a problem?

Prisoner's dilemma tournament results

by AlexMennen 1 min read9th Jul 2013124 comments


The prisoner's dilemma tournament is over. There were a total of 21 entries. The winner is Margaret Sy, with a total of 39 points. 2nd and 3rd place go to rpglover64 and THE BLACK KNIGHT, with scores of 38 and 36 points respectively. There were some fairly intricate strategies in the tournament, but all three of these top scorers submitted programs that completely ignored the source code of the other player and acted randomly, with the winner having a bias towards defecting.

You can download a chart describing the outcomes here, and the source codes for the entries can be downloaded here.

I represented each submission with a single letter while running the tournament. Here is a directory of the entries, along with their scores: (some people gave me a term to refer to the player by, while others gave me a term to refer to the program. I went with whatever they gave me, and if they gave me both, I put the player first and then the program)

A: rpglover64 (38)
B: Watson Ladd (27)
D: skepsci (24)
E: Devin Bayer (30)
F: Billy, Mimic-- (27)
G: itaibn (34)
H: CooperateBot (24)
I: Sean Nolan (28)
J: oaz (26)
K: selbram (34)
L: Alexei (25)
M: LEmma (25)
N: BloodyShrimp (34)
O: caa (32)
P: nshepperd (25)
Q: Margaret Sy (39)
R: So8res, NateBot (33)
S: Quinn (33)
T: HonoreDB (23)
U: SlappedTogetherAtTheLastMinuteBot (20)