Image via Nintendo/YouTube

Have you ever been monstering a race in Mario Kart and then, blam, the blue shell hits and you’ve got a few seconds of teeth-grinding frustration while you wallow about and the other players catch up with you?

If you have, congratulations, you’ve been caught in a feedback loop.

What are feedback loops?

In simple terms, a feedback loop is a game system that takes the output of a game and introduces it as an input.

The blue shell in Mario is one of the most famous examples of a feedback loop.

You are winning (the output) and because you are winning, someone at the back of the race tail gets the blue shell and can only hit you with it because you are in the first place (the input).

There are also two specific kinds of feedback loops, positive and negative, which can have a dramatically different effect on the player.

Positive and negative feedback loops: what are they?

The term feedback loop comes from biology and chemistry, where the output of a reaction either increases or decreases the rate of the reaction.

In those terms, a good example of a positive feedback loop would be your body’s reaction to being cut. Once the tissue has been damaged, the body releases a chemical that stimulates platelets in the blood to activate.

These platelets stem the flow of blood and begin to close the wound. They also give off their own version of the same chemical which causes more platelets to become active.

The ongoing output of the reaction to the cut creates an input that increases the speed at which it is healed.

Getting sweaty is a good example of a negative feedback loop. As your body temperature increases, you sweat. The sweat evaporates and cools your skin through evaporative cooling.

In this case, the output of the reaction, your sweating, reduces the speed of the reaction, your body temperature rises.

Feedback loops in games are actually very similar to these examples.

Positive feedback loops allow players to build on their successes, translating to a feeling of accomplishment and rewarding the player for playing well.

Negative feedback loops make the game more challenging.

They are the E=MC2 of game design, the harder you push, the more the negative feedback loop pushes back. This stops the player from snowballing success to the point where the game becomes unenjoyably easy.

How do game designers use feedback loops in games?

The best games provide balance. Make a game too easy and the player quickly loses interest because all their in-game accomplishments start to seem hollow and unearned.

Make the game too hard, and players will bounce off the difficulty curve and not return to the game. Games are meant to be relaxing and entertaining, not a Mobius strip made of cheese graters.

The difficulty with obtaining balance is that most games set their difficulty right at the beginning of the game when the player has the least amount of experience with the game itself.

While most modern games will allow you to adjust the difficulty during the game, there is the perception that this is some kind of defeat to overcome.

Certain games, think Wolfenstein: The New Order or Doom Eternal, name their difficulty levels in a way that really leans into this idea. In Wolfenstein: The new Order, the 4 levels of difficulty are called “Can I play, Daddy?”; “Don’t hurt me.”; “Bring ‘em on!” and “I’m death incarnate!”.

By comparison, positive and negative feedback loops are in-game elements that allow the game designers to dynamically control the game difficulty. They act as sliders that prevent the game from becoming too easy or too hard.

Examples of positive feedback loops

Positive feedback loops help to build the players success into more successes and can be seen in games like.

Call of Duty

One of the most famous examples of a positive feedback loop is the killstreak system in certain Call of Duty games. To sum it up, if you got a certain number of kills without dying, you were given perks that made it easier to kill other players. This created somewhat of a snowball effect that meant that the most successful players got progressively more successful, while the other players found it increasingly difficult to compete with them.

Activision and Treyarch tried repeatedly to balance the killstreak mechanic, before eventually phasing it out, making it an excellent example of how a single positive feedback loop can negatively impact game balance.

Hades

Supergiant’s game of the moment, is a rogue-lite, meaning there is no saving your progress as you attempt to get Zagreus out of Hades, and dying means you go right back to the start. However, each room you complete on your way out of Ancient Greek hell gives you certain rewards, allowing you to gain new skills and perks, get new weapons, and move the story forward with certain NPCs.Each run rewards the player’s successes with a better chance of making it out of the Underworld on the next run.

XCOM

Strategic turn-based tactics game, XCOM uses an experience-based system to level up your alien-fighting soldiers, making them better in combat and harder to kill. The more fights you get your soldiers into, the more experience they earn and the more effective they are. Combined with the variable difficulty of the missions, and the perma-death system, this feedback loop encourages you to shuffle your roster around to get access to the widest spread of skills and create a level of redundancy that offsets any losses.

Examples of negative feedback loops

Negative feedback loops allow the game to have a balancing relationship with the player’s actions. The more successful the player is, the harder the game pushes back. In a perfect world, this makes the game challenging for all levels of players and play styles.

Mario Kart

The blue shell (also known as the spiny shell) and the other catch-up mechanics associated with the distribution of pickups in Mario Card has often been used as a prime example of a negative feedback loop. Because the game is designed to be less competitive than other racing games, the addition of these mechanics gives everyone a chance to participate in the race, no matter their skill level.

Hades (again)

One of the reasons that Hades has come into line for the amount of praise that it has received, is that it has both positive and negative feedback loops that create a balanced and entertaining structure to the game. The primary negative feedback loop in the game is the fact that, when you die, you lose all your progress. Given that there are no healing items, you will die. What stops this from becoming tedious and irritating is the fact that you need to die in order to move the plot forward.

Supergiant’s attention to both the primary gameplay loop and the secondary metaplot means that every failed run feels like a new opportunity to go and experience the rich game world they’ve created.

Cultist Simulator

The acclaimed indie card game Cultist Simulator uses a notoriety mechanic to throw a wrench in your Lovecraftian plans. The more you progress through the game, the more likely it is that you will attract unwanted attention. The presence of meddlesome do-gooders adds another level of difficulty to the game to offset your progress, as they remove your followers, mess up your card placement plans and even end the game by throwing you in spooky-boi jail.

What is their role in crafting player experiences?

As we mentioned earlier, some of the primary issues with creating a balanced game revolve around preventing the game from being too hard, too easy, and the difficulties of setting a difficulty at the beginning of an evolving interactive experience.

By introducing both positive and negative feedback loops into a game, designers can build a dynamic level of difficulty control.

The player’s successes are reinforced through positive feedback loops while their increasing ability to overcome the core game’s challenges is curtailed by the use of negative feedback loops.

While many players might regard dynamic difficulty with a certain amount of suspicion, there are examples of it being used to great success.

The best examples of this are probably Supergiant game’s ability to make repeatedly dying interesting in Hades or Resident Evil 4 “hidden” dynamic difficulty system.

When done well, feedback loops enhance the player’s experience by maintaining a consistent level of challenge throughout a game, while still rewarding the player for their achievements.

This, in theory, creates the holy grail of the games design world, a game that maintains that feeling of challenge and achievement for the entirety of the game.

Why should you, as a game designer, care?

From the study and understanding of systems across games, recurrent patterns emerge that can be viewed as general solutions to common game design challenges. When using models that represent games at a sufficient level of abstraction, these patterns become immediately apparent. If, of course, you’re using the right tools.

To this end, Machinations diagrams are specifically designed to represent game systems in an accessible way that stays true to games’ structural features and dynamic behavior. The power of Machinations is that the diagrams, with just a click of a button, can immediately produce quantitative data from thousands of simulated play sessions, without a playable prototype, real player interaction, or coding your own Python scripts or VBAs for simulations.

Investing time in picking Machinations up, will not only unlock your skill of analyzing any game system but power you up with a tool that allows you to experiment efficiently and craft perfectly balanced games, before writing a single line of code. There are plenty of resources that will help you get started like webinars, live streams, and last but not least, a growing community of game designer peers to get inspired by.

Fireside Chat, Episode 1 w/ Joris Dormans