scrape_r_rational/data/cache/3pd01v.md

[D] Monday General Rationality Thread

Post:

Welcome to the Monday thread on general rationality topics! Do you really want to talk about something non-fictional, related to the real world? Have you:

• Seen something interesting on /r/science?
• Found a new way to get your shit even-more together?
• Figured out how to become immortal?
• Constructed artificial general intelligence?
• Read a neat nonfiction book?
• Munchkined your way into total control of your D&D campaign?

Comments:

• u/alexanderwales:

  I read *The Art of Language Invention* over the weekend, which I found quite interesting. I recommend it if you have any interest in the complexity of language, or in conlangs themselves. I think it might have been a little confusing if I hadn't had a linguistics background, because it's trying to cover *lots and lots* of things that a proper linguistics textbook would spend hundreds of pages on, but the advantage here is that it's not as dry as most textbooks are. (The book was written by the guy responsible for making Dothraki and Valyrian more than the minor sketches that GRRM put into the books.)
  
  I personally think conlangs are *cool* but usually complete overkill for use in fiction; you could teach the reader the language, but that's probably not a good idea if you also want a plot that moves anywhere. Since most readers aren't linguists or conlangers, that effort is wasted.
  

  • u/xamueljones:

    True, but if you take the time to make a language sound consistent and like an actual language instead of randomly throwing words together then you can have an extra layer of immersion to make the story flow better.
    
    For example in *The Hobbit* and *Eragon*, the made up languages added a nice touch to the world building without slowing things down due to how they contributed to the story and the authors didn't let it take attention away from the plotline.
    
    As a counter-point, J K Rowling never intended her magic spells to be an actual language, so it sounds a bit ridiculous to have her characters to be speaking psuedo-Latin whenever they used their magic. It only works, because of how it's taken so seriously by her characters.
    

    • u/alexanderwales:

      There are varying degrees of conlangs. I'm into the ones that sound like languages, but that's only the first 2% of actual language creation. You choose which sounds you're going to be using, you pick some patterns for consonants and vowels, then you string them together into something that scans well. But *actually making a language* is different, because you need phonology, intonation, inflection, agreement, tense, etc. Stuff [like this](http://imgur.com/a/G9vac) is what I mean when I'm talking about overkill.
      
      (My friends and I are actually doing a Harry Potter themed version of D&D where one of the house rules is that you have to speak all of your spells in Dog Latin. So "Hold Person" becomes "*Holdus personi!*". So that's fun.)
      

• u/blazinghand:

  For once, I'm not DMing my D&D campaign-- I'm a player. The DM seems pretty good and moderately experienced. Our campaign setting is modern world + parahumans who only began emerging in the past 30 years or so. The PCs are all powered.
  
  Following a series of violent and destructive clashes between powered humans, the government policy for dealing with this tiny minority of empowered people is effective imprisonment. The government sends parahumans to live in a walled-off section of Montana with power-suppressing machines built into the walls and ground to prevent their powers from doing anything. Also, the government has secretly added a chemical to most processed food that harmlessly suppresses powers.
  
  The plot of the campaign is that basically we think this is a bad thing and are willing to lie, steal, kill, and terrorize in order to end this policy. It's pretty clear my character is willing to do all this stuff, but she was a criminal and a murderer before she got her powers. 
  
  Somehow, everyone seems totally on-board with the terrorism. I tried suggesting we quit our lives of villainy (since our secret identities were still secret) and start a political movement. We could write blog posts about how C41B (the secret chemical that suppresses superpowers) causes autism or obesity or something, and support Whole Foods which stocks C41B-free food. Run for local government, pass bills, etc. Maybe get started in Seattle and have our political movement work South, then East. Sadly, the rest of the party wanted the violent terrorism approach so I followed along.
  
  During a snack break I discussed with the others that the government was doing something fundamentally reasonable. After all, if our world was one in which one in every hundred thousand people had the innate ability to level mountains and shatter buildings with impunity... well, *I'd* want the government to shut these people into internment camps. Heck, I'd even support the idea of a secret harmless chemical that inhibits these peoples' powers. Superpowers *scare* me. I was not persuasive enough! I don't think they're really thinking it through, though. I don't think they understand the visceral fear that they'd have if such people really existed. 
  
  I guess at some point I started viewing our party as a group of villains, even though the DM and the other players don't see that way. I don't mind this. Maya, my character, is definitely a villain. She's not even the worst. She's not the cop-killer-- that's Abigail. Baldwin hasn't murdered anyone yet, but that's more due to his power set than his will. Particleese has. Maya has. 
  
  Nobody thinks twice about the bodies we leave behind in our quest to destabilize a society that's already on the brink, a society that's barely controlling the parahuman menace. When the chips fall and we've given the empowered minority free reign to burn this world, will we be remembered as heroes? Probably not. We won't be remembered as anything, because this fledgling Democratic civilization will come to an end. We had millennia of dictatorship, a couple brief centuries of almost-just, almost-liberal rule, almost escaping despotism, serfdom, and the divine right of kings-- before being plunged back into the darkness by parahumans.
  

  • u/Transfuturist:

    Are you arguing to others as players, or as characters? Infusing Maya's behavior with this recalcitrance would make for interesting drama and plots, but if you're seriously trying to argue that the other players shouldn't have fun doing what they want, you'll be in for a bad time.
    

    • u/blazinghand:

      Oh, I'm having fun in the campaign, and Maya has no compunctions about what's going on. The issue isn't that the campaign isn't fun, it's that I don't think we're the heroes of the story. We're definitely villains. We're hip villains with good motivations to do what we do, but in the end, when we're successful, the world will be a worse place for most people. Maya is okay with this.
      

• u/ulyssessword:

  I'm currently in the planning stages of making a video game, and I'm having a bit of trouble figuring out how to code the AI to do what I want.
  
  The simplest way to describe the problem is "biased rock paper scissors".  Imagine a game of RPS, to 100 points,  except that every time rock beats scissors, that game counts as two points instead of one.  What's the optimum strategy in that case? It's not 33/33/33% anymore.
  
  Now imagine that the two players had *different* payoffs for various outcomes.  How would you solve this in the general case? 
  
  Edit for clarification: Both players know the payoff matrix, and (to start with) I'm assuming that both players will play the Nash Equilibrium, and will add in the biases later.  It is also Zero-sum, as it's a simple 1v1 arena battle with a binary win/loss condition.
  

  • u/alexanderwales:

    Do the players know each other's payoffs?
    
    > Imagine a game of RPS, to 100 points, except that every time rock beats scissors, that game counts as two points instead of one. What's the optimum strategy in that case? It's not 33/33/33% anymore.
    
    This depends almost entirely on your opponent.
    
    * If facing an opponent who throws randomly, the ideal strategy is 100% rock, because you'll average 2 points per 3 rounds.
    * If facing an opponent who throws 100% rock, the ideal strategy is 100% paper, because you'll get 1 point every round.
    * If facing an opponent who does tit-for-tat (they do whatever you did last), the optimum strategy is to pick rock, paper, scissors, rock, etc., because you'll get 4 points per 3 rounds.
    
    See [this RPS](http://www.rpscontest.com/leaderboard) computerized competition for strategies - all have their code exposed. Basically, what you're asking for is *complex* because it depends on knowing what the other player's strategy is, which at higher levels depends on trying to hide your own strategy from them.
    

  • u/Chronophilia:

    Sounds like you're looking for the [Nash Equilibrium](https://en.wikipedia.org/wiki/Nash_equilibrium) of the game. In your example - where you get 2 points for winning as rock, and the game is still zero-sum - the Nash equilibrium is where both players use a random strategy which plays 25% rock, 50% paper, 25% scissors.
    
    The Nash Equilibrium gives the strategy where neither player has any incentive to change, *as long as the other player doesn't change either*. There is usually some element of randomness, but not always. There may be more than one Equilibrium, such as in the [Stag Hunt](https://en.wikipedia.org/wiki/Stag_hunt).
    
    Oh, and in the [Prisoner's Dilemma](https://en.wikipedia.org/wiki/Prisoner's_dilemma), the Nash Equilibrium is defect-defect, even though cooperate-cooperate is better for both players. This is one way in which classic game theory fails to model the real world. But that sort of problem doesn't happen in zero-sum games (where the players are strictly opponents, with no incentive to cooperate with one another).
    

    • u/electrace:

      >Oh, and in the Prisoner's Dilemma[3]  , the Nash Equilibrium is defect-defect, even though cooperate-cooperate is better for both players. This is one way in which classic game theory fails to model the real world. 
      
      I don't see how that is failing to model the real world. What conclusion are they reaching that is false? Also, defect-defect is only the NE in a one-shot game. 
      
      In an infinite game, a better strategy is tit-for-tat (leading to both players cooperating forever).
      
      When you get into high amount of rounds, but finite games where things get tricky.
      

      • u/Chronophilia:

        The Prisoner's Dilemma demonstrates how players can get a better outcome by following a non-equilibrium strategy, so the Nash equilibrium isn't a useful guide to playing the game.
        
        "Both players always defect" is still a Nash equilibrium for the iterated prisoner's dilemma - neither player gains from using a different strategy as long as the other one keeps playing all-defect. I'm fairly sure "both players cooperate on the first game and play tit-for-tat thereafter" is not a Nash equilibrium - at the very least, you can improve on that strategy by suddenly defecting in the very last game.
        

        • u/electrace:

          >The Prisoner's Dilemma demonstrates how players can get a better outcome by following a non-equilibrium strategy, so the Nash equilibrium isn't a useful guide to playing the game.
          
          Unless you can control both players (in which case it isn't a real prisoner's dilemma ), it's a fantastic guide for playing the game. 
          
          You aren't looking for the best payoff for both players, only the player that you have control over. Since you can't control the other person, defect is the better strategy in both cases.
          
          If you *do* have control over both players, the options become CC, CD, DC, DD, in which case, of course, you would choose CC.
          
          >"Both players always defect" is still a Nash equilibrium for the iterated prisoner's dilemma - neither player gains from using a different strategy as long as the other one keeps playing all-defect
          
          For an infinitely repeated game, technically yes, it's an equilibrium, but it's a pretty stupid one. Playing tit-for-tat has the potential for an incredible long-term return, at the risk of only one game's lost points. 
          
          >I'm fairly sure "both players cooperate on the first game and play tit-for-tat thereafter" is not a Nash equilibrium - at the very least, you can improve on that strategy by suddenly defecting in the very last game.
          
          Which is why I specified that it was an infinite game I was talking about. There is no last game. 
          
          In finite games, as you say, you can defect in the last round. Knowing that you opponent will defect in the last round, you have no incentive to cooperate in the second to last round, which leads you opponent to defect in the third to last round... which eventually leads to you both defecting in the first round. Backward induction sucks...
          
          There are ways to get around this (which normally involve changing aspects of the game, but traditionally, all finite games of prisoner's dilemma with rational players and perfect information have a NE of always defect.
          

    • u/Seth000:

      > In your example - where you get 2 points for winning as  the Nash equilibrium is where both players use a random strategy which plays 25% rock, 50% paper, 25% scissors.
      
      Could you give me any advice to be able to estimate the Nash equilibrium of such a game (mixed strategy is the term I think). Did you have this example memorized, or could you calculate it in your head?
      

      • u/electrace:

        Ok, so for **symmetric zero sum games**, the expected value of any strategy must be 0 at Nash Equilibria points. Why? Because if you were earning a negative expected return, you could always copy the other player's strategy. And if you're both players are playing the same strategy, (while they sum to 0), then they must both be 0.
        
        So, all you really have to do is take  rock, paper, and scissors, and find the strategy that will make it sum to 0 through a system of equations.
        
        Rock: Against paper, -1, against rock, 0, against scissors, 2  
        
        0 = -1P + 0R + 2S
        
        Paper: Against paper, 0, against rock, 1, against scissors, -1
        
        0 = 0P + 1R - 1S
        
        Scissors: Against paper, 1, against rock, -2, against scissors, 0
        
        0 = 1P - 2R + 0S
        
        And the final equation, P + R + S = 1 (All percentages sum to 100%), which can be rewritten as...  
        P = 1 - R - S
        
        From the Rock equation... 0 = -1(1 - R - S) + 0R + 2S = -1 + R + 3S
        
        1 = R + 3S
        
        From the Paper equation... 0 = 0(1 - R - S) + 1R  -1S = R - S
        
        S = R
        
        (from 1 = R + 3S, and S = R), 1 = R + 3R = 4R  ----> **R = .25**  ----> **S = .25**
        
        And finally (from P + R + S = 1), P + .25 + .25 = 1 ----> **P = .5**
        
        
        If you can do that in your head, I salute you.
        

        • u/Seth000:

          Thanks, You're helping.
          
          Your scissors formula should be 0=1P-**2**R right?
          

  • u/Salivanth:

    Here you go:
    
    https://gamebalanceconcepts.wordpress.com/2010/09/01/level-9-intransitive-mechanics/
    
    Your 2-1-1 example is located reasonably early in the post, and it goes into a lot of detail from there, including asymmetric scoring. (where each player has a different payoff matrix) This should be exactly what you're looking for.
    

  • u/MugaSofer:

    Is this zero-sum? Because the two players could probably co-operate to get more than either could in competition.
    
    More generally, I think this becomes a game of second-guessing your opponent, so there may *be* no single winning strategy. (Just as it's strictly better to predict your opponant's moves in RPS than to be completely random.)
    

  • u/Escapement:

    This seem like the sort of situation that would evolve a Nash Equilibrium, with a mixed solution. For an example of one method of calculating Nash Equilibria that is pretty general, I found [this matlab script](http://www.mathworks.com/matlabcentral/fileexchange/27837-n-person-game/content/npg/npg.m) which requires only [this function](http://www.mathworks.com/matlabcentral/fileexchange/27837-n-person-game/content/npg/gamer.m). This works for any n-person game where you can explicitly define payoffs for each combination of strategies.
    
    ~~The nash equilibrium for a RPS game where rock wins 2 points and other wins are 1 point, I *think* works out to choosing Rock 20% of the time and each of the others 40% of the time - but I am not an expert on this sort of thing.~~ edit: see comment below
    
    Scholarly reference: http://www.pnas.org/content/36/1/48.full
    
    Lesswrong stuff: http://lesswrong.com/lw/dc7/nash_equilibria_and_schelling_points/
    

• u/Predictablicious:

  I found this over the weekend: http://en.arguman.org/
  It's an online tool to dissect arguments and structure agreement and refutation.
  

  • u/traverseda:

    The level of discourse is not as high as I'd like. Anyone feel like using it if I set up a clone focused on rationalists?
    

    • u/electrace:

      Only if you actually have a way to keep the level of discourse high, which is tough to do without mods.
      

• u/LiteralHeadCannon:

  I think cellular automata would seriously benefit from a probabilistic component.  At its simplest - how would Conway's Game Of Life change if the following addenda were added?
  
  1) Living cells with two neighbors have a .1% chance of dying on each turn.
  
  2) Dead cells with two neighbors have a .1% chance of coming to life on each turn.
  
  That's just a Conway's Game Of Life mod, but I think it might be even more interesting to design entire cellular automata from the ground up around probabilities, rather than certainties.
  

  • u/Frommerman:

    That would be interesting, but it would also be strictly different and way less interesting in the ways that Conway's Life is. CL is cool because it's a set of four simple, intuitive rules which combined produce a turing complete system, technically capable of any and all arbitrary calculation. Fungal life would be interesting to watch a few times, but would then lose interest because it wouldn't be possible to actually construct things in it.
    

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