From slot machines to video game loot boxes
Summary
We often think that many of the phenomena that occur around us are random, that is, that they happen by chance. For example, whether a coin lands on heads or tails seems, at first glance, to be a matter of chance. Or when we roll a die, we also consider the number we get to be random. In these cases, we can't know what the result will be, and, most importantly, we think that all the options have the same probability of occurring.
The idea of chance is present in loot boxes. Loot boxes in video games combine the direct purchase of an item with the mechanics of a virtual slot machine, based on probability and intermittent reinforcement . In fact, many voices denounce them as a form of disguised gambling aimed at minors. But, to begin with, is their operation truly random? What psychological techniques lie behind their design that make them a risk for some people?
How are slot machines designed?
The heart of every modern slot machine is the random number generator (RNG). It's not a physical part, but a highly complex computer algorithm that constantly cycles through thousands of numbers per second, even when the machine isn't being used. We'll assume it's "random," but it's important to emphasize that a computer can never create truly random numbers.
The key is that each part you see of the drum (top image), that is, the 7, or the image of the cherries, or the piece where you see the word BAR, has associated numbers; these numbers will determine when the machine will stop on each square or piece of the drum.
This means the machine generates random numbers, but it will only stop on 7 when the random number is 24, for example; however, for it to stop on the word BAR, it will do so when the random number is 38, 39, 40, 41, 42, 43, 44, or 45. In other words, as shown in the figure, even though the word BAR occupies much less physical space, it has a much higher probability of being where the reel will stop. This technique is called reel paper or the near miss illusion . Therefore, slot machines are often programmed to display near misses (for example, two jackpot symbols land right on the payline, but the third symbol lands just above or below).
This is an intentional psychological design feature to encourage the player to keep betting. Studies show that the brain reacts to near misses in a similar way to how it reacts to an actual win; that is, it activates the brain's reward centers, encouraging the player to continue playing because they feel they were "so close" to success that they believe their luck is about to change.
The role of video game design in addiction
Sensory overload and positive reinforcement
The unpredictable nature of the game is highly addictive. Because the player never knows which spin will result in a win, they feel compelled to keep betting. To maintain this state, so-called sensory overload and positive reinforcement are used. This means that when a player wins, even a small amount, the machine immediately springs into action: loud, celebratory music blares, lights flash, and a cascade of virtual coins appears on the screen. The excessive sensory feedback—the sound and sight of winning—is often disproportionately large compared to the actual monetary value of the win. The act of winning is associated with a powerful and immediate release of dopamine.
The player believes he can influence the outcome, even though it is already predetermined, making him feel more responsible for near misses or losses and encouraging him to try again.
The Illusion of Control and the Naming Effect
Perhaps one of the most pernicious aspects is the illusion of control over the game , since many modern slots include "skill stops" (the ability to manually stop the reels) or features like the "nudge." Crucially, the outcome is already determined; that is, the number we mentioned earlier is set before the reels even start spinning. But this makes the player believe they can influence the result, even though it's scientifically impossible, increasing their commitment , making them feel more responsible for near misses or losses, and encouraging them to try again.
Another psychological technique is the use of "virtual money," that is, inserting euros, but to acquire, for example, credits, so that with just a few euros you can get a large number of credits. In this way, the credits feel less "real" than real currency, and, therefore, bets reach higher levels.
Loot boxes : the leap into video games
It is estimated that the loot box model, globally, will have generated more than $20.3 billion by 2025, demonstrating that it is a continuously growing business model (González, 2021).
While in some establishments it is possible to buy bags or envelopes of a certain price without really knowing what they contain, in the world of video games, this practice has acquired a new dimension with the so-called loot boxes .
Loot boxes are virtual items purchased with real money or in-game currency (whether earned or purchased) that contain a random selection of other virtual items . The player buys the box without knowing exactly what they'll get, similar to a loot bag. They combine the direct purchase of an item with the mechanics of a virtual slot machine, relying on probability and intermittent reinforcement to encourage repeat purchases. But how does it work?
Warning signs of video game addiction
The GACHA system: the origin of loot boxes
The outcome of a loot box isn't truly random; it's controlled by a random number generator (RNG), similar to the slot machines we saw earlier. The term "Gacha" (or Gacha Game ) comes from the Japanese onomatopoeia "gachapon" (or Gashapon), which is the sound a vending machine makes when you turn the crank and the capsule drops.
Gacha systems in video games are a monetization method where players spend real money (or in-game currency) to receive a random virtual reward . It's the core mechanism of loot boxes and relies on probability to obtain rare or powerful items. This weighted content is also seen in sticker packs, where the most sought-after items have a low probability of appearing (for example, stickers of the most popular soccer players), while less desirable ones have a much higher probability of appearing—what we know as duplicate stickers.
The main psychological mechanic of 'loot boxes' is based on intermittent reinforcement: the player knows that there is a possibility of obtaining the rare item they want, but never knows when it will happen.
These systems originated and achieved unprecedented success in Asia (specifically Japan, China, and South Korea). The Japanese population had grown up with physical Gacha machines. Buying a capsule containing a random collectible toy was a common activity. The game system simply digitized an already established and beloved collecting experience. In that context, the culture of collecting entire series was very strong, and Gacha capitalized on this desire by offering themed character series that compelled players to complete them.
A very important factor in these Asian cultures is the high pressure to succeed. This system exploits pride and status through "legendary" characters that have a low drop rate and confer high social status and pride within the gaming community. In this way, players who obtain the rarest characters or equipment (through the Gacha system) have a competitive advantage, forcing other players to participate in the Gacha system to remain relevant.
Family, school and community prevention in the use of screens
The infamous "fear of missing out" (FOMO) factor is used in limited-time events (banners) to offer ultra-rare characters for a short period. This sense of urgency pressures players to spend money immediately. The emotional connection with the characters is also exploited, as these characters often have high-quality designs, complex backstories, and fan service (waifus or husbandos).
Although it may seem complicated to implement, the Gacha model is perfect for mobile gaming : it allows for short sessions, easy purchases (microtransactions), and consistent progression. Furthermore, historically, Gacha regulation in Asian countries has been more lenient than that of Western gambling (although this is changing, especially in China). This has allowed the model to flourish without the legal restrictions that affect slot machines.
Psychological techniques in loot boxes
The main psychological mechanic of loot boxes is based on intermittent reinforcement . The player knows there's a chance of obtaining the rare item they desire, but never knows when it will happen. This uncertainty keeps the anticipation and the impulse to buy stronger than a guaranteed reward. Most of the time the player loses (obtaining a common item), but the system occasionally rewards them with a slightly better item, reinforcing the buying behavior.
'Loot boxes' are considered by many to be a form of hidden gambling aimed at minors, and they warn of the risk of addiction they can generate.
So, what can we find in loot boxes? Well, everything from items classified as "cosmetic," such as skins , emoticons, avatars, banners, etc., which don't affect gameplay (they're purely visual) and are the most common type in games classified as "non-gambling"; to weapons, stat boosts, character cards, and reduced cooldown times that do directly affect gameplay, which can lead to "pay-to-win" situations, since players can buy a competitive advantage.
Regulation of loot boxes: a legal and ethical debate
Loot boxes are the subject of intense legal and ethical debate, as many governments and organizations consider them a form of hidden gambling aimed at minors , due to their reliance on probability and the uncertainty of the purchase. Countries such as Belgium and the Netherlands have banned or severely restricted loot boxes containing functional items, arguing that they violate their gambling laws.
Critics argue that loot boxes exploit players' psychological vulnerabilities (especially those with addictive tendencies) by monetizing anticipation and uncertainty . Although there has been significant progress (such as the approval of a draft bill by the Council of Ministers), specific regulation of loot boxes in Spain is still under legislative review. Political and social consensus points to a ban on their use by minors and an obligation of transparency for adults, acknowledging the risk of addiction associated with these mechanisms.
