Chernobyl stands as one of the best demonstrations of the destructive power of positive feedback. Huh? I don’t mean positive feedback as in the mouse made it through the maze give him a food pellet. In systems design positive feedback happens when some part of an output is fed back and added to the black box that operates on an input. Thus as the input increases the output tends to grow even more. The growth can be exponential…..explosive. Negative feedback means that the sample taken off of the output is subtracted from the process in the black box. Thus it tends to stabilize a system. If input increases a huge amount and the output starts rising as a result then the negative feed back restrains the growth in the output. Pressurized water reactors that are the workhorses of the nuclear power industry operate on a negative feed back principle. A key design principle is to have a negative temperature coefficient of reactivity. Basically as the temperature of the water increases it becomes a poorer moderater and thermal fission slows down. At Chernobyl due to bad design, bad operating practices, bad decisions and bad luck the graphite moderated reactor temporarily achieved a positive temperature coefficient of reactivity. Increased heat meant increased power which in turn generated more heat. In a fraction of a second the power output increased exponentially and a steam explosion occured. As the Ghostbusters would say that was a bad thing.
So what does this have to do with strategy game design? A game is really just a bunch of black boxes with connections running between them. The players operate the inputs to the system by pressing buttons. Buttons can move pieces, draw resources, play cards and do all other manner of strange and fantasmagorical things. The output of the entire game system could be thought of as a group of some type of victory numbers. Each player has a victory number that represents how strong their position is to win the game. So the proposition is that if you wanted to you could take any strategy game and map it out as a system. Draw out the player inputs, the operations performed in the boxes, and let the outputs be each players claim on “winning” the game.
So when thinking about a game in this manner, perhaps while you are doing design, positive and negative feedback should be something you keep in mind. The Chernobyl event is an extreme version of positive feedback but that doesn’t mean you should exclude positive feedback from your design. Rather you should just take pains to manage it and ensure that it can’t go Chernobyl on you.
I’m going to discuss positive feedback on two different scales in my next entry. One is a meta scale and concerns the runaway leader syndrome and the other is a finer “systems” type scale involving the set collection mechanic.
Just a note as well. I am heading off to Finland next week to accompany my famous Art Historian wife as she delivers a lecture on performance art for the Finnish Arts Council. Besides being fantastically beautiful, Finland is one of the most wired countries in the world so it should be business as usual for me. One of the advantages of being an indie developer is the show goes wherever I do.