Nudge and game design

Welcome to the second part of the article about nudges in game design, where I talk about how game design can intersect the content of the book “Nudge: Improving Decisions About Health, Wealth, and Happiness" by Richard Thaler and Cass Sunstein. You may find the first part here (https://www.pietrodammora.com/post/nudge-and-game-design-part-1)

Social Pressure

This is actually one of the strongest nudges, which has proven its effectiveness time and time again. In Amsterdam, simply informing citizens that “most people in Amsterdam recycle” increased recycling rates by 5%. It’s a simple, low cost but effective strategy that can be employed in a great variety of situations. People are inclined to follow the social norm and, by showing something as a popular option, we encourage them towards it. This nudge is especially useful in games with an online component, where we can show the behavior of other players. A good example is the finale of NieR Automata, where (no spoilers) people are encouraged to sacrifice themselves after receiving help from others who made the choice to sacrifice.

Limiting decision space

If you want to guide players towards the right choice, it’s useful to reduce the options at their disposal, to avoid mental overload and reduce the chances of a wrong decision. Puzzle games often tweak the difficulty of a level by adjusting the decision space.

Take this level from Baba is You (a puzzle game where your character can form phrases to change the logical behavior of the objects). The phrase “Baba-is-You”, even inside the walls where Baba is, wouldn't change the solution to this puzzle. But by placing it behind the wall the designers help players focus on what’s inside the walls to solve the puzzle.

Anchoring

Anchoring is a cognitive bias where individuals rely heavily on the first piece of information (the "anchor") they receive when making decisions. This initial information sets a reference point and influences subsequent judgments. The reference point can be arbitrary: for example, starting a negotiation with a high price when selling a car leads buyers to settle for a higher price than they might otherwise. The objective is not to sell the car for the initial price, but to set a starting point that will advantage the seller.

However we (hopefully) don’t want to trick our players this way. When you have control over the order in which players see the content of your game, you can use this effect to guide them to certain choices or simply to increase the excitement. If, for example, the starting weapon in your game deals 4 damage, it will feel much more exciting to find a weapon that deals 15 damage at the start of the next level. For the same reason, we should avoid anchoring players to very convenient or powerful values, to avoid reduction in the excitement they will feel later.

Anchoring can also be used to increase clarity in your game. In Plants vs Zombies, the Peashooter is the first damaging plant players see. When George Fan had to design a plant dealing double damage as the Peashooter, he made it shoot two peas, so players could intuitively understand its value. As players had the anchor of the damage of a single pea, they were able to intuitively understand the value of the Repeater, more than if he had the plant shoot another kind of projectile or a bigger pea.

Fear of Losing Options

People hate losing options in their choices and tend to keep them open if possible.

In a popular experiment by Dan Ariely, people were given a computer program where they had 3 doors, each granting a random amount of money unknown at the beginning of the experiment. The rules were:

People have 100 clicks
Selecting a door costs 1 click, but once inside, each clicks grants money
Each doors gives money randomly in a range that is different for each door

As the random ranges were different, there were doors more valuable than others. People simply explored all the options until they found out the most valuable option, then stuck with that until the end of the 100 clicks.

Nothing special until this point. But then he changed the program: whenever a door is not clicked, it starts to disappear. If not chosen many times in a row, that option is lost forever. In this version of the experiment, even if people figured out the most valuable door, they kept on spending clicks to keep them all available, losing a lot of money.

In many games we see this effect. When a choice would commit players, making them lose the alternatives, players are reluctant and try to procrastinate the choice as much as possible, even when keeping the option open has a cost.

Furthermore, showing an option as temporary, can induce players to pick it more than the others. For example, in Sifu, there is an age limit to some skills, so players tend to learn them first. Sometimes, choosing based on fear of losing options is the right call, but we have to always keep in mind that players would do it even when it isn’t the case.

Salience

Salience (or saliency) is the property by which something stands out, typically from contrasts with its neighboring items. When an option stands out from the rest, it draws more attention and consideration. This is why we see different and bright colors to highlight offers or special prices in a supermarket.

Let’s take Plants vs Zombies once again. They wanted to encourage players to plant the Sunflower first to build a strong economy. However, early playtests showed that many players preferred planting the Peashooter, to have immediate protection against the zombies. This caused a ripple effect where players didn’t have enough suns to face the zombies later in the level. How did they fix this? Well, at the beginning, Sunflowers and Peashooters had the same cost. By halving the Sunflower price, they encourage them to plant it for two reasons. The first is a technique we already saw today: limiting the decision space. For a while, at the beginning of each level, players have money to buy the Sunflower but not the Peashooter.

The other reason that encourages planting the Sunflower is indeed its salience. As the game highlights all plants you have enough suns to buy, the Sunflower naturally gets more attention as the only highlighted plant in the first moments of the game (as it’s the cheapest plant for the first couple of levels).

Ciao!

That’s all for today and for articles about Nudge, hope you enjoyed both parts. See you next week for another article.

Nudge and game design - Part 2