Death Trap (Game Theory)

Thinking about any scenario that places your loves one(s) in danger is rather morbid but for the sake of exploration we’ll overlook that, still, being in any bad situation one you immediately see the worst result and not the best solution. There are a variety of ways to look at this problem, some really in-depth analyses require some sturdy maths skill others merely ethical or moral stances. The collective name for the understanding this and similar problems is called Game Theory, and it is not, as the name implies, a soft subject.

The problem illustrated above is one I learnt at around 12 y/o, but there is a similar depiction made quite recently. In the recent Batman film, The Dark Knight, The Joker places bombs on 2 ships and gives the detonators to the opposing ship saying either one of you dies or you all die. There are other moments in that film that have an economy behind them and we’ll go into them later.

Mathematical Overview

(No sums or equations here, honest)

All end results can be shown in a table, or matrix, clearly showing a Live/Die for each party/boat in each situation.

Party A
Acts Passive
Party B Acts Die, Die Die, Live
Passive Live, Die Die , Die

This Normal form works for both my problem and the Jokers Ultimatum, there doesn’t seem to be a best action. In a perfect relationship you would both want each other to live and want to save each other but attempting to do so would kill them. If the civilians kill the guilty they become the guilty, the Joker wins but a ferry survives. Which takes us onto an…

Ethical Overview

As with Newtons Third law, “To every action there is an equal and opposite reaction”, by pushing the button you are willingly setting yourself up to kill someone, by not acting the responsibility of the outcome is the perpetrator of the situation. So if both parties do nothing they may loose their lives but they can happily know that they didn’t kill each other. This however does not work with a boat load of people, as they don’t have a button each so there a social ramifications such as being on a surviving boat but not wanting to have pushed the button. And of course they know there is a Batman out there so they can wait for him to save them, whereas in the prison cell they do not have that hope.

Philosophical Overview

Either scenario is preposterous, nobody would actually go to these lengths to commit this crime, if you were to actually find yourself in this situation it is most likely fictitious and as such humming a sticking your fingers in your ears is a viable solution until you wake up. As Homer (J. Simpson) would say, if I don’t see it its not happening!

This is just a talk out of the Joker’s Ferry game, there are 2 other obvious ones (at least to me) the 3 second clip were the bank robber asks the Joker if the shotgun is empty, saying yes/no and being wrong/right has some interesting results. And the robbery itself seems like a variant of the Pirate Booty Game

I’ve just explored 3 ways of looking at that situation I’m sure there are a variety of others, feel free to drop a comment below. Lastly I don’t expect that if you were in as dire situation as this you would consider the problem as rationally but I suppose that is the advantage of practising and theoretical discussions.

Weight on the Mind

Learning to think differently is quite hard. Teaching others’ to think differently is harder still because you can only check their comprehension and not their understanding of what you are trying to teach. A favourite riddle of mine for such things is below.

  • You have eight weights equal in appearance.
  • One of them is heavier (denser) than the rest.
  • Minimum number of weightings until you can always find the odd one?

How many more weightings would it take for 12 weights?

How many more weightings would it take for 57 weights?

My thought for the day is how you’ve worked it out. A very cleaver thought in my humble opinion.