Click here to participate. Entries must be submitted on October 18th, 2020 or earlier.
Entry is now closed.
In 2017, Zvi posted an exciting story about The Darwin Game, a variation of iterated prisoner's dilemma.
I will run my own version of the game in the week following October 18th, 2020. You do not have to know how to program in order to participate. I will code simple bots for non-programmers. If you do know how to program then you may create your own complicated bot.
Here are the rules. Changes from Zvi's original game are in brackets [like this].
For the first round, each player gets 100 copies of their program in the pool, and the pool pairs those programs at random. You can and often will play against yourself.
Each pair now plays an iterated prisoner’s dilemma variation, as follows. Each turn, each player simultaneously submits [an integer] from 0 to 5. If the two numbers add up to 5 or less, both players earn points equal to their number. If the two numbers add up to 6 or more, neither player gets points. This game then lasts for a large but unknown number of turns, so no one knows when the game is about to end; [I guarantee it will be at least 100 turns per iterated prisoner's dilemma].
Each pairing is independent of every other pairing. [You do know what round of the game it is and that you are facing an opponent. If you face a copy of yourself you are automatically awarded the maximum 5 points per round (2.5 points per bot). You otherwise do not know any history of the game to this point.] Your decision algorithm does the same thing each pairing.
At the end of the round, all of the points scored by all of your copies are combined. Your percentage of all the points scored by all programs becomes the percentage of the pool your program gets in the next round. So if you score 10% more points, you get 10% more copies next round, and over time successful programs will displace less successful programs. Hence the name, The Darwin Game.
Your goal is to have as many copies in the pool at the end of the last round as possible, or failing that, to survive as many rounds as possible with at least one copy.
[I will attempt to iterate until there is a stable equilibrium.]
I will add some silly bots of my own to make the early game more interesting.
Instructions for non-programmers
Please give a simple explanation of what you want your bot to do. Write it with mathematical precision. If your specification is even slightly ambiguous then you will be disqualified.
Instructions for programmers
Write a program of the following format.
class TitForTatBot():
def __init__(self, round=0): # Edit: Changed "1" to "0"
self.turn = 0
self.round = round
self.previous = None
def move(self, previous=None):
self.turn += 1
if self.previous:
output = self.previous
self.previous = previous
return output
else:
return 2
# Edit 2020-10-11: The above code is wrong. The properly-implemented TFT `move` method looks like this.
# def move(self, previous=None):
# self.turn += 1
# if previous == None:
# return 2
# else:
# return previous
Your class must have an __init__(self, round=1) intializer and a move(self, previous=None) method. You may write your class in Python 3 or Hy.
Unlike Zvi's original game, you do get to know what round it is. Rounds are indexed starting at 0. The previous parameter of the move method is an integer indicating what your opponent did last iteration. If it is the first iteration then previous equals None.
A new instance of your class will be initialized in each round. You may save whatever information you want into the class instance's fields but you may not save information between rounds or between class instantiations. The move method must always return an integer from 0 to 5 inclusive.
You may import standard libraries like random, scikit and numpy.
Coordinating with other players
Anyone can play, but only players with a Less Wrong account that existed before I declared this tournament will be allowed to coordinate out-of-game. This rule exists to prevent players from submitting multiple entries to this contest and self-coordinating. Coordinating with other people is encouraged. Coordinating with yourself between multiple separate entries is cheating.
Click here to participate. Entries must be submitted on October 18th, 2020 or earlier.
Entry is now closed.
If you're participating in the contest and you want to win, I have a proposition for you:
Howdy! You've probably looked up Zvi's past Darwin game that directly inspired this one. A group of players formed a clique who recognized each other, cooperated among themselves and defected on everyone else. They nearly wiped the board, but they were preyed upon by a member who played both sides.
What they missed was a way to guarantee that all members apply the decided strategy. They had no way to enforce it.
But we have a way.
I call it CloneBot: a bot who checks that its opponent has the exact same code as itself. No way to cheat that! It guarantees that every member of the clique does the same thing. Moreover, there'll be a way to cooperate optimally, avoiding losing the first rounds to coordinate. The clique are gonna be the most efficient ccoperators.
But in the end we're all gonna tie, it's boring. I want to take a chance at winning!
So do I. This is why the clique are only going to collaborate until a predefined round. After we've eliminated the competition, we can have a dramatic showdown among ourselves. Cool, no? In the code, there's gonna be a separate function that's called only after a given round. The code checker will verify that the function is only called at the right time, but will ignore what is inside.
What will CloneBot do?
Depends on the proportion of clones. If we're a big group, CloneBot will straight up defect against outsiders by playing 3. Otherwise, CloneBot will cooperate, but make sure opponent does not gain more than itself.
With its clones, CloneBot will cooperate by alternating 2-3. Who gets the first 3 will be determined fairly before the first turn starts.
Ok, but I don't want to find myself in a small clique that's going to lose.
You don't have to commit to submitting CloneBot right away. All you need to do is contact me to say you're in, conditional on the clique being large enough. By default, contact me privately. If you want, you can roll a D6, and if you roll 6, join me publicly right here.
A few days before the deadline, if we're 5 or less, I'll just announce that the critical mass was not reached. But if we're more than 5, I will make public the names of all who contacted me to join the group and crush the competition. If I post your name at that moment, you must submit CloneBot.
I like the idea, but I wish X instead of Y.
Every detail is open to discussion for about 3 days. After that, this post will be updated, and every person who expressed their desire to join will be informed of the changes and asked to confirm their participation.
Where do I find CloneBot?
I'm considering making the code public.
Let the best clique member win :)
We were five hundred, but with swift support
Grew to three thousand as we reached the port
(Le Cid)
It's been an exciting week, I've had lots of fun, thanks everyone who shared ideas, and thanks lsusr for swiftly and kindly answering all my questions. Now is time for the final act.
You will receive a personal message shortly.
That is all.