Goblin Game [From the Archives]

My “Day I Left Pennsylvania” led me to some archived website posts (before blogs were invented) I had written many years ago. I’m re-posting them now. Bear in mind that most of the content in this series is over 5 years old. I have left the content more or less intact. I have removed some links and added some others — but that’s it. Enjoy!


goblin_gameYes it may be a magic card, but it inherently possesses a fundamental of game theory. For those of you who are not familiar with what that image to the right is, it is a card from the game Magic: the Gathering ,however it’s origin is unimportant, nor is whether or not you understand the nuances of the numbers and whatnot. The text in the lower-half of the card is what is important here. Allow me to elucidate in real-life terms….money!:

Let’s say that everyone (3 or more people) has 20 dollars. The game proceeds like this:

  1. Each player hides a certain number of objects (poker chips, for example). The number must be greater than 1.
  2. After everyone has their objects hidden, all players simultaneously reveal their objects to other players. The number of objects hidden is significant here, and should be recorded.
  3. Everyone immediately loses the amount of money equal to the number of objects hidden, this goes into a “pot” in the middle. If a player has hidden more objects than he has money, all of his money is put into the pot instead.
  4. Whoever had set aside the fewest objects loses half of their remaining money, rounded up.
  5. Repeat steps 1 – 4 until only one player is left with any money. That player then wins it all.

Understand how to play? More importantly, do you understand how this illustrates game theory? All players must consider the actions of other players when making their own decisions. Continue reading