Game Design Gone Loopy

I bumped into Jesse Catron on The Game Crafter chat when I first joined the small online board game design community. Jesse sent me a copy of his prototype Pond Farr and it was a real hit with my group. It’s lighthearted, has a good degree of take-that and player interaction, and beautifully incorporates a deckbuilding mechanic into a board game. It’s a really clever game and falls into the “I wish I thought of that” category.

By playing Pond Farr (soon to be published by Gryphon Games as Salmon Run) and interacting with Jesse, you quickly learn two things: One, Jesse is really clever and thoughtful. And two, he’s a ridiculously nice guy. I was really glad he took the time to write a guest column for this blog.

Guest Column by: Jesse Catron

I was honored when Grant asked me to write something for his blog, but I really had no idea what to write about, nor did I know whether anyone would care to read what I have to say.  I certainly don’t presume to be an expert in game design, nor an expert in writing articles. Nonetheless, after a few weeks of drawing blanks, I finally thought of a topic that I find interesting and relevant to game design. It’s also one which hasn’t really been covered (at least not to my knowledge).  Despite the title, I will not be writing about crazy game designs or crazy game designers.  I’ll leave that for another article.  Instead, I thought I would write about feedback loops and how they relate to game design.


Feedback loops are fairly common in many aspects of life. Some examples include the thermostat in your home, the hormonal systems of the human body, and even the guitar sounds of the late Jimi Hendrix. All are controlled by feedback loops. In general terms, a feedback loop is a control of a system in which the output of the system cycles back to affect the input of the system. This feedback can either be positive or negative. Note that it is not positive and negative in a sense of good and bad, rather that the feedback amplifies the output (positive) or diminishes the output (negative).

When your home’s heating system heats the house to a certain temperature, that higher temperature triggers your thermostat to turn off your furnace.  If the temperature falls too low, the low temperature triggers your furnace to turn back on. You can quickly see that feedback loops of this nature can be good at regulating a system into stability.  This is the hallmark of a negative feedback loop. The initial output of the system (increased temperature) affects the input of the system such that the future output of the system is regulated or diminished (your furnace turns off so the temperature will not continue to increase).

Just as negative feedback loop stabilizes a system, a positive feedback loop tends to destabilize a system. The self-perpetuating nature of the amplification in a positive feedback loop will send the system out of control. It’s like holding a microphone too close to a loudspeaker; the audio output of the speaker is looped into the input of the microphone, which then results in increased sound (output) out of the speaker. This increased (louder) output of the speaker is again picked up by the microphone and results in an ever-increasing output of sound until nothing but a high-pitched squeal can be heard.  Left unchecked, a positive feedback loop will spiral out of control.

So what does this have to do with board games?  If you analyze board games in terms of feedback loops, you can see how commonplace they are and how useful they can be in game design. The ability to recognize feedback loops and identify how they can cause or solve design issues is a useful skill for a game designer.

Let’s take a look at how a feedback loop can cause a problem in a game. One that comes to mind is the run-away leader. In this scenario, one player takes an early lead and can’t be caught by the other players. This is often, but not always, caused by a positive feedback mechanism.  When dealing with a run-away leader problem, you either need to eliminate the positive feedback loop or add something to keep it in check, often a negative feedback loop.

For example, in Settlers of Catan, the player with the most productive settlements will generate the most resources, which enables him to build more settlements and gain even more resources. This is a positive feedback loop. A player with favorable rolls and/or strategically well-placed initial settlements can often take an early lead. However, there are several factors in place to mitigate this potential run-away leader.  Firstly, the randomness of later dice rolls may slow this player. However, relying on bad luck is not a good method of hampering a run-away leader. A more useful method is to introduce a negative feedback loop to the system, which is often known as a catch-up mechanic. In Settlers, this is done via the Robber. The Robber is placed on a resource hex to prevent production at that location. In a game with a clear leader, the other players will invariably place the robber on location that will most hamper the resource production of the leading player, slowing down the leader and allowing the others to catch up. The Robber is not a flawless catch-up mechanism, however. The leading player will likely have the greatest ability to buy Soldier cards and move the Robber to lessen its effectiveness at slowing him down. The run-away leader is also regulated by the trading mechanic in the game.  Most players will be less likely to trade with the leader, or if they do trade, they drive a harder bargain. This is usually quite effective.

You may be thinking that negative feedback loops (stability) are always good and positive feedback loops are always bad (instability).  While often true, this is not always the case.  For example, in Monopoly (I realize not the best game design), there is a positive feedback system in which the player collects monopolies or properties that generate wealth. This allows the player to collect more and better properties and therefore collect even more wealth.  Granted, there are mitigations to the loop like the luck of the rolls, but the positive feedback system in Monopoly is essential to drive the game to its conclusion and prevent it from dragging on forever. One player’s wealth must grow and grow (amplify) until the other players are bankrupt.  Many player-elimination games are designed this way.

Perhaps the best example of the usefulness of feedback loops can be found in deck-building games. Let’s use Dominion, the granddaddy of deck-building, as an example.  If you think about it, what are you actually doing when you play Dominion? You’re essentially trying to build the most efficient and powerful positive feedback system.  Let’s set aside the Victory cards for a moment and examine the Treasure cards. You begin with a number of weak Copper cards. You play some Copper cards to gain a better Silver card. The output of you playing Copper cards is a Silver card, which in turn affects the future output of your deck. That Silver card will cycle back into your hand, which gives you more buying power and therefore enables you to eventually purchase Gold. The buying power of the deck is amplified with each cycle. This is a basic positive feedback loop.

Though a bit more complicated, the Kingdom cards work in a similar fashion.  Most Kingdom cards amplify your deck’s ability to play more cards per turn and/or make more purchases (or better purchases) and those abilities are compounded with each cycle of the deck.  A few Kingdom cards, like Militia or the Witch, work by introducing negative feedback into your opponents’ positive feedback engine, but these are exceptions.  Being that Dominion is a game centered around creating a positive feedback system through the Treasure cards and most of the Kingdom cards, would it therefore have an inherent run-away leader problem?  No, and the reason it doesn’t is the genius of the design in my opinion.  Donald X. Vaccarino wisely used a negative feedback system as the victory condition. The Victory cards hamper the positive feedback system you are building, yet are essential to winning the game.  Deck-Building games are great examples of the effective use of both positive and negative feedback loops.

As an aside, while most early deck-builders like Dominion utilize the construction, development, and management of these feedback systems as the whole of the game, the future of this game genre is to use it as one component of a greater game with a larger scope.  This is already occurring with games like A Few Acres of Snow and Mage Knight.  I digress.

Clearly, both positive and negative feedback loops can be used effectively in game design.  Positive feedback loops can, but not necessarily, cause run-away leader problems.  It is vital to be able to recognize them when they do cause problems and to know how to effectively use negative feedback loops to keep them in check. In my own design, a deck-building racing game called Salmon Run (the game formerly known as Pond Farr), I had to be especially cognizant of its positive feedback system and utilize sufficient negative feedback systems to keep the leader in check.  No one wants a run-away leader in a racing game!  Fortunately, I succeeded and most games are very close.

Thank you for reading! I hope you find this article useful in your game designs.

What are some other examples of games with good (or bad) positive and negative feedback loops? Contribute in the comments below!

Update! Daniel Solis created a really cool infographic to visually break down the post written by Jesse Catron (and others, as cited on Daniel’s site). I wanted to include it here so that you have the WHOLE enchilada in one place.

5 thoughts on “Game Design Gone Loopy

  1. This is outstanding. Thanks so much for opening my eyes to this phenomenon within game design. I’m intrigued by harmonics in physics, and I can see how this could apply to our hobby.

  2. Pingback: Salmon Run: An Interview with Jesse Catron | Hyperbole Games

  3. Pingback: Jesse Catron Interview

  4. Pingback: Salmon Run: An Interview with Jesse Catron | Hyperbole Games

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