4. week

Level .05 - Feedback Loop

Feedback Loop, positive and negative feedback in games

Motivation

Before starting today's topic, let's review what we know about the MDA framework - what words are behind the acronym and their meaning concerning game design.

Today we will go back to dynamics and look at a special kind of dynamics, which is feedback or feedback.

We already talked about feedback, but in a completely different context - in connection with game testing, when you received feedback from the playtester on the result of your work. However, this time we will look at the feedback regarding the created rules for the game and the resulting dynamics. And we will distinguish two types of feedback, namely positive feedback and negative feedback.

Positive Feedback Loop

So let's look at the positive feedback first. Let's start with a simple comparison. Positive feedback works the same as when you bring the microphone close to the speaker. The volume will start multiplying because the microphone and the speaker will start to "bind" or "catch feedback." In the same way, we can look at positive feedback in games - it is a kind of amplifier. And in the game, it is a situation that strengthens the overall game output and directly impacts aesthetics.

A positive feedback loop occurs when a game achieves an achievement that makes it easier to achieve other achievements. Or in other words - when a player manages to get something in the game that will facilitate his further progress. But if the importance of the positive game loop is too great, then the first player who manages to get into the lead is guaranteed to win the whole game. So, positive feedback directly impacts the game balance.

Positive feedback often occurs in games where the conditions of victory are defined in numbers - by playing the game itself, these numbers increase. For example:

  • in the game Monopoly it is about getting money,
  • in the game Super Mario Bros, it is about getting points for various activities.

However, there are games where the numerical evaluation of the game state only sometimes leads to the fact that the more (of something), the more apparent the winner. An example is the game Chess, in which more figures do not necessarily mean that the player has the upper hand. In chess, checkmate can be achieved even with fewer figures than the opponent.

Let's see an example of positive feedback on The Guardian Legend on NES. After finishing the game, you get access to a special gameplay mode. In this mode, you are rewarded with power-ups at the end of each level according to how many points you get: The higher the score, the more power-ups you get to the next level. It's a positive feedback loop: If you get a high score, you get more power-ups, which makes it easier for you to get an even higher score in the next level, which gives you even more power-ups, and so on.

Note that the reverse is also true in this case. Consider what happens if you get a low score. You'll get fewer power-ups at the end of each level, making your next level more difficult, likely resulting in an even lower score, etc., until you're so far along that it's almost impossible to progress.

Three Features of Positive Feedback Loop to Avoid

Three characteristics of positive feedback that designers should avoid:

  1. They tend to destabilize the game, as one player gets further and further ahead (or behind).
  2. They cause the game to end faster.
  3. They put emphasis on the early game, since the effects of early-game decisions are magnified over time.

Steps in Feedback Loop

Feedback loops usually have two steps, but they can also have more. For example, real-time strategies have a positive feedback loop with four steps:

  1. Players reveal the map.
  2. This gives them access to more resources.
  3. This will allow them to buy/develop better technology.
  4. This will allow them to build better units (thanks to which they can reveal even more of the map, find more resources...).

Other Examples

Most "4X" games, like the Civilization and Master of Orion series, are usually built around positive feedback loops. As your civilization grows, it will allow you to generate resources faster, making you grow more quickly. By the time a serious conflict with your enemies begins, one player is usually so far behind that it's not much of a challenge anymore, as the core of the positive feedback loop drives the game's idea that someone who gets ahead easily in the early stages of the game becomes more distant in the later stage of the game.

The physical sport of Rugby has a bit of a positive feedback loop: When a team scores points, they start over with the ball on their end, making them a little more likely to score another point. So, the advantage is given to the team that just won another advantage. This is unusual for most sports, which often give the ball to an opponent after they have successfully scored.

The same goes for the game Pexeso. One of the rules says that if the player finds a pair/pair of the same cards, he makes the next move again, which increases the chance of getting another pair of cards for him. So for finding a pair, he is rewarded by being able to get another pair.

Negative Feedback Loop

Negative feedback is the opposite of positive feedback. However, it is about balancing (balancing) relationships. When something happens in the game, such as one player gaining an advantage over the other players, the negative feedback ensures that the other players can catch up, reducing the winning players' effort to maintain their lead.

An example can be the game Super Mario Kart. In racing games, it's more fun when the player is in the middle of a group of cars than when the player is too far ahead or too far back. The result of this is the standard addition of a negative feedback loop in games of this genre: If the player gets ahead of the group, the opponents start cheating, find better power-ups and achieve unrealistic acceleration to make it easier for them to catch up to the first one. This makes the game more difficult for the player to maintain or extend the lead. This peculiar feedback loop is sometimes referred to as "rubber banding" because the cars behave as if they were connected by rubber bands, pulling the leaders and laggards back to the group's center.

Similarly, the reverse is also true. If the player finds himself behind, he will find better power-ups, and opponents will slow down to allow him to catch up. This makes it harder for the behind player to drop even further. Again, both of these examples are negative feedback loops. "Negative" means that the dynamics become weaker with each iteration. It has nothing to do with whether it positively or negatively affects the player's position in the game.

Three Features of Negative Feedback Loop to Avoid

Three characteristics of negative feedback that designers should avoid:

  1. They tend to stabilize the game, causing players to tend towards the center of the pack.
  2. They cause the game to take longer.
  3. They put emphasis on the late game, since early-game decisions are reduced in their impact over time.

Other Examples

Most physical sports like football and basketball have the rule where the opposing team gets the ball and is given a chance to score a point after your team scores. This reduces the chance of one team scoring over and over again.

Developer Story: My grandfather was generally better at chess than the children he taught to play. To make the game more challenging, he devised a rule: If he wins, in the next game, his opponent may remove his figure from the square at the beginning of the game (first 1 pawn, then 2 pawns, then a king or bishop, etc. according to how the child lost). Whenever my grandfather won, the next game should be much harder for him to win again, increasing the chance that he might start losing.

Use of Feedback Loops

Is the feedback good or bad? Should we include them in the game or avoid them?

As with most aspects of game design, it depends on the situation. Sometimes the designer includes them in the game on purpose. And other times, when they are discovered, it will be decided whether to keep them or remove them.

Positive feedback can be useful as it can end the game quickly when the player starts doing well. But they can also have the opposite effect: weaker players trying to catch up to the first can be frustrated that they no longer have a chance.

It's the same with negative feedback, which prevents strategies from gaining the lead as soon as possible and keeps the feeling that all players still have a chance to win. But it can also have the opposite effect: the best players are actually punished for success.

So what makes feedback "good" or "bad" from a player's perspective? It can be seen rather as a player's view of the fairness of the game system. And it is possible to find out with a playtest.

Eliminating Feedback Loops

If you've discovered that your game contains feedback and you've decided to eliminate it, you have two options.

The first is its direct removal. Each feedback consists of three parts:

  1. Sensor - monitors the state of the game,
  2. Compactor - decides whether to take action based on the values monitored by the sensor,
  3. Activator - modifies the game state when the compactor decides to do so.

Example - racing game:

  • The sensor detects the player's distance from other cars.
  • The compactor detects if the distance has exceeded the critical distance.
  • The activator causes other players to speed up/slow down.

The solution, in this case, is to remove the sensor, change or modify the compactor, or modify or remove the activator.

If you don't want to remove feedback, the solution is to add reverse feedback, for example. For example, racing games:

  • If the other lagging cars accelerate, the player in front can also accelerate, resulting in an earlier end of the race, but none of the players will be disadvantaged or advantaged.
  • The first player can get better power-ups to compensate for the higher speed of the lagging players.

Additional Resources