Your Book Review: Addiction By Design

Finalist #10 of the Book Review Contest

[This is the tenth of many finalists in the book review contest. It’s not by me - it’s by an ACX reader who will remain anonymous until after voting is done, to prevent their identity from influencing your decisions. I’ll be posting about two of these a week for several months. When you’ve read all of them, I’ll ask you to vote for your favorite, so remember which ones you liked. If you like reading these reviews, check out point 3 here for a way you can help move the contest forward by reading lots more of them - SA]

I was scrolling through TikTok videos a few weeks ago when I came across a TikTok-sponsored video telling me to stop scrolling and go outside. I was confused. Here I was, perfectly willing (nay, wanting) to spend hours watching dance routines and drawing tutorials I had no intention of copying, but TikTok wanted me to stop? Why? Shouldn’t they have been taking advantage of me to maximize “eyeballs,” “time per session,” and “user engagement”?

One explanation is that TikTok is a good corporate citizen that helps its users maintain responsible screen time habits. Another explanation comes from Natasha Dow Schüll’s excellent book Addiction by Design: Machine Gambling in Las Vegas (2012). Schüll talks about gambling machines, people who use them, and the addictions that develop between the two. I think the conclusions she draws are applicable not only to the gambling industry, but also to other peddlers of vice like TikTok.

The Machine

Sometimes employees at Netflix think, ‘Oh my god, we’re competing with FX, HBO, or Amazon’ … [W]e actually compete with sleep.

- Reed Hastings

Randomness is addictive, in rats. B. F. Skinner learned that when he created his eponymous rat boxes. The boxes had levers that, when pressed, dispensed food pellets. Rats in boxes where one press resulted in one pellet pressed the lever when hungry. But rats in boxes where one press randomly resulted in no, one, or many pellets, became addicted to pressing the lever. That mammalian attraction to randomness lies at the heart of all gambling.

But machine gambling is not like other kinds of gambling. The book overflows with metaphors straining to describe how machine gambling is the supercharged version of table games like poker, blackjack, and roulette. Machine gambling is deforestation ruining the rainforest of diverse table games. Machines are invasive kudzu outcompeting and killing the native table games. Machine gambling is the crack cocaine to table games’ cocaine.

In about two decades, machine gambling went from being a side attraction to keep wives busy while their husbands played table games to the source of 85% of casino profits. You know how shopping malls have benches for husbands to sit on while their wives shop in stores? Imagine that those benches became the mall. (If you’re reading this in 2025, shopping malls were, uh, a collection of permanent pop-up stores under the same roof.)

The first time I went to Vegas, I knew a few tricks casinos would use to encourage me to gamble too much. I knew the hotel rooms were purposefully cheap, to entice me to visit Vegas. I knew casinos would have neither windows nor clocks, to help me lose my sense of time. I knew they would be full of bright lights and loud sounds, to overstimulate me. I knew nothing. Those tricks are old hat, as quaint as doilies. Machine gambling is a brave new world.

Machine gambling comes in the form of many games, but one example is enough to illustrate the pattern, so let’s discuss slot machines. Slot machines are games with reels with a variety of symbols on them, like cherries, diamonds, or the number 7. (Fun fact: fruit symbols were initially used on slot machines during the prohibition era to disguise them as gum vending machines.) The game is simple. The player spins the reels. If they land to show symbols in a row, the player wins. Because of their simplicity, these machines are favored by new gamblers and tourists.

Back when Moore’s Law was just Moore’s Prediction, slot machines were mechanical devices. The player would pull on a mechanical lever, which caused reels to spin. The reels would eventually slow down and then stop. The symbols in the middle of the screen when the reels stopped dictated whether the player won or lost.

Now, slot machines are digital. The lever, the reels, the symbols — they are all ones and zeros untethered from reality. This gives machine designers a terrifying amount of flexibility. They can optimize the game to maximize its addictivity.

First came the obvious optimizations. These are optimizations any hotshot business consultant would suggest. Designers replaced mechanical levers with buttons and physical reels with video screens. This made the games three to four times faster. The quicker each game, the more money gamblers can spend during their gambling session. Quicker games are also more addictive. Bally, a casino company, targets 3.5 seconds per game.

Another obvious optimization was to replace physical coins with a card system. Coins make fun jingling noises when players win, but that’s about their only advantage over cards. Cards are quicker to use, less likely to cause blockages in the machine, and allow casinos to track their owners throughout their gambling sessions. Also, gamblers using cards don’t feel like they are spending “real” money, which means they end up spending more.

Next came the reality distorting optimizations. These are optimizations any game designer not too concerned with ethics would suggest to you. One reality distorting optimization is adding “near misses” to games. Near misses are features that suggest to the gambler that they just barely missed out on winning big. They make the game addictive because gamblers try to assuage the pain of barely losing by immediately playing again. They also make gamblers think that winning is easier than it actually is.

An easy way to add near misses is to expand the viewing window so that symbols above and below the main line become visible. The more symbols the gambler sees, the more likely she is to experience a near miss. A more devious way to add near misses is to use “teaser strips,” which are animations of spinning reels loaded with winning symbols. When the gambler presses spin, teaser strips are played first to make the gambler think the reels are full of winning symbols, and are replaced with the actual symbols when the reels stop spinning.

Another reality distorting optimization is to increase the number of ways a gambler can win. In old-school slot machines, the only way to win was to get winning symbols on the main line: the three symbols in the middle of the screen. Now, there are more ways to win than Horatio dreams of in his philosophy.

Originally, the only way to win was to get winning symbols on line 1, shown in yellow on the top left. Contemporary machines allow you to win if you get winning symbols on any of these 50 (and sometimes more) lines! These are not intuitive, straightforward ways of winning. You cannot convince me that lines 28, 39, or 45 are reasonable. These are lines drawn by game designers who acted like they were getting paid by the line.

The proliferation of lines creates a damned if you do, damned if you don’t situation for gamblers. If they don’t bet on all the possible lines in a game, then they are doomed to see near misses. After all, in a game with 50 possible lines, at least one of the lines is bound to be a winner. If a gambler bets only on line 1, she is doomed to see other lines win, and suffer the pain of almost having won. On the other hand, if the gambler bets on all 50 lines, she is going to lose a lot of money every turn. On every turn, she will make 50 bets, of which she might win one or two. This may feel like a win, but she will be losing money on the net. Even penny slots lose money fast when the gambler bets 50 cents on 50 lines each game, and makes a new bet every few seconds.

But the game designers still weren’t done optimizing. Next came the reality smashing optimizations. These are optimizations that probably involved game executives calling lawyers and whispering, “is this actually legal?”

One of these reality smashing optimizations is LDWs, or losses disguised as wins. This is when a gambler wins a small amount of money on a bet, and the machine reacts as if it’s the Fourth of July. Bells whistle, lights brighten, horns blare, coins jingle, and screens flash. This happens even if the gambler bet 50 cents and won 20. Even though the gambler experienced a net loss, the machine does its best to convince her that she won. This is the “doesn’t matter, still won” counterpart to these lyrics from Lonely Island’s I Just Had Sex:

She kept looking at her watch
(Doesn't matter, had sex)
But I cried the whole time
(Doesn't matter, had sex)
I think she might've been a racist
(Doesn't matter, had sex)
She put a bag on my head
(Still counts)

But even LDWs are child’s play compared to the pièce de résistance of reality smashing optimizations: reel mapping. At the heart of every digital slot machine is a random number generator (RNG). When the gambler presses the spin button, the machine gets a number from the RNG and translates it into a set of symbols. This translation process is called reel mapping, and it is where the most creatively devious game design happens.

Reel mapping enables weighting, which means certain reel symbols are more likely to show up than others. The standard reel has 22 symbols, and in an ideal world, each symbol would show up with a probability of 1/22. However, with weighting, certain reel symbols are given a much higher probability of appearing. Losing symbols show up much more often than winning symbols. Reel mapping also enables clustering, where losing symbols directly above or below a winning symbol are weighted more heavily than others. This allows winning symbols to show up above or below the main lines, thus creating a near miss.

Reel mapping cuts any connection the game has to reality. A mechanical slot machine will produce a jackpot about once every 10,000 (22*22*22) spins. A digital slot machine can lengthen those odds to once every 20,000,000 spins, or more. If a digital slot machine paid out as often as its reel implies it should, without reel mapping magic, it would pay out 185% of the time.

The Player

Who has never killed an hour? Not casually or without thought, but carefully: a premeditated murder of minutes. The violence comes from a combination of giving up, not caring, and a resignation that getting past it is all you can hope to accomplish. So you kill the hour. You do not work, you do not read, you do not daydream. If you sleep it is not because you need to sleep. And when at last it is over, there is no evidence: no weapon, no blood, and no body. The only clue might be the shadows beneath your eyes or a terribly thin line near the corner of your mouth indicating something has been suffered, that in the privacy of your life you have lost something and the loss is too empty to share. Mark Z. Danielewski, House of Leaves

Before I read this book, I had an unsubstantiated theory for why people gambled: it’s because every gambler thought he would be the one to beat the odds. In other words, people gambled to earn money. Sure, gamblers knew that most other gamblers lose money, but that just means that gambling is a high-risk high-reward activity. Gamblers were willing to bear the risk in order to have a shot at the reward.

When it comes to machine gamblers, my theory is completely incorrect. People who spend hours and hundreds on machine games are not after big wins, but escape. They go to machines to escape from unpredictable life into the “zone.”

The primary objective that machine gambling addicts have is not to win, but to stay in the zone. The zone is a state that suspends real life, and reduces the world to the screen and the buttons of the machine. Entering the zone is easiest when gamblers can get into a rhythm. Anything that disrupts the rhythm becomes an annoyance. This is true even when the disruption is winning the game. Many gamblers talk about how winning the game brings them out of the zone, and they actually dislike winning for that reason. For some gamblers, the very act of pressing buttons to play the game disrupts the rhythm. These gamblers use autoplay modes on games that offer them, and jerryrig an autoplay mode on machines that don’t by jamming something into buttons to keep them pressed. They don’t want to chase a win or pick their lucky numbers, they want to disappear into the zone.

You might have heard of the horseshoe theory in political science, which claims that the far-left and far-right are much closer to each other than either is to the center of the political spectrum. Imagine a similar horseshoe for states of existence. In the center, you have daily life: activities like eating, cleaning, and working. On the right, you have altered states of existence where time and individuality cease to matter: Csikszentmihalyi’s flow, meditative trances, or just intense absorption in interesting work. On the left then, you would get similar altered states of existence, but those which are destructive instead of creative, like the zone machine gamblers desperately seek.

I’ve felt the attraction of this dark flow when I’m searching for something to escape from real life for just an hour or two. For me, it takes the form of scrolling through a social media feed. It could be Facebook, Twitter, Reddit, TikTok, or YouTube. I don’t look for anything in particular. I just want the comfort of scrolling through endless meaningless content. Sometimes, I don’t even fully absorb the content. If you took my phone away from me and asked me to name five things I saw, I doubt I’d be able to answer. The content just flows through me while I escape into a zone where real life doesn’t matter.

Schüll explicitly makes the comparison to Csikszentmihalyi’s flow. Flow requires four elements: sub-goals, clear rules, immediate feedback, and challenge-skill balance. Gambling offers at least the first three. Playing through each individual game is a sub-goal. Each game has clear rules: bet money and press spin. Each game only takes a few seconds, offering immediate feedback. The last element, challenge-skill balance, is not fully present in gambling. Gamblers can increase the challenge of the games by playing more lines on slot machines, or by graduating to games that require more skill, like video poker. Still, gambling doesn’t exactly require “skill,” per se, but gamblers manage to achieve flow even without that element.

Flow ends when the person achieves his goal. For example, a chess player experiencing flow will come out of it when the chess game ends. A surgeon experiencing flow will come out of it when the surgery ends. Gambling, unlike those activities, has no natural endpoint. Gamblers can repeat the individual games as many times as they want. There is no larger goal to build towards and achieve. The only endpoint for gambling is when the gambler runs out of money. This is referred to as “playing to extinction” in the gambling-research world.

The book is full of heartbreaking stories about what gamblers endure on their path to extinction. They sacrifice their bodies, their time, and their relationships. Sharon, for example, spent four days at a casino, trying to lose all her money to reach extinction. At the end of this ordeal, she came home to sleep, but she found three nickels in her bedroom. The thought of not having spent all her money bothered her so much that she drove back to a casino immediately to lose those last three nickels.

The book’s description of machine gambling addiction forced me to rethink two stereotypes I had about gambling addicts. First, I used to think gambling addicts were bad with money. After all, why else would they waste so much money on a destructive habit? However, the addicts described in the book are not profligate spenders. Many of them economize in order to save up money they can gamble with. They are not reckless spenders in all areas of their life, just this one. Second, I used to think that gambling addicts “lost control” when they gambled excessively. But the addicts in the book use machines as a way to gain control in their lives. In front of a machine, the world is simple: they place bets and lose a little bit of money on each turn. The gamblers are in control of this machine world. It is the world away from machines where the prospect of losing control in frightening ways looms. Away from the machines, life is long and full of terrors.

The Addiction

Guns don’t kill people, people kill people



Before I go into what the book says, let me set the stage about what the book leaves mostly unsaid. Good writers write with an intended audience in mind, but they also write with an intended foil in mind. They educate the intended audience and distinguish themselves from the intended foil. Schüll’s foil is the following idea: gambling addiction is a personal failing. In NRA-speak, machines don’t create gambling addicts, gambling addicts create gambling addicts. Gambling addicts are formed when people lack self-control, take too many risks, or don’t budget their time or money appropriately. The machines have nothing to do with it. If the machines didn’t exist, gamblers would find some other self-destructive outlet.

Underlying Schüll’s foil is a fairly common instinct that people have about the difference between substance addictions (to drugs, alcohol, or nicotine) and behavioral addictions (to gambling, eating, or exercising). Most people think that substance addictions are caused by things, but behavioral addictions are caused by people.

In other words, if most people hear a story about a kindly old grandmother who was prescribed opioids for a backache, and became an opioid addict, they blame the opioids for causing her addictions. Without the opioids, she would still be that kindly old grandmother. In contrast, if most people hear a story about a kindly old grandmother who started going to casinos to have fun on slot machines, and became a gambling addict, they blame the grandmother for having a defective character. Even if she hadn’t visited casinos, she would always have had that character defect.

Just this month, the Economist said, “Critics of e-sports offer moral objections, too. They are addictive. Prince Harry has called for ‘Fortnite’ to be banned for this reason. [... This argument is not] very convincing. The idea that an activity, rather than a substance, can be addictive is contentious among doctors.” The state of affairs is that a smart magazine can dismiss the idea of activities being addictive in just one sentence. It’s not games that are addictive, it’s that gamers are weak!

I am not an addiction researcher. I don’t know the formal definition of addiction. It is possible that the formal definition of addiction precludes the idea of activities being addictive. But that doesn’t change the fact that activities can absolutely be addictive given the layman’s definition of addiction. If the formal definition of “addiction” does not cover activities that drive compulsive, repetitive, unceasing behavior, then we need a new term that does cover it. But the lack of a word to describe addictive activities doesn’t mean that addictive activities don’t exist. The Sapir-Whorf hypothesis is not that strong.

What would it be like if we talked about substance addictions the way we talk about behavioural addictions? In that world, we would see a lot more discussion of, and research building upon, the Rat Park experiment. That experiment tested a ludicrous hypothesis: opioids are not actually that addictive. The researcher separated rats into two groups. The rats in one group were caged and isolated from each other. The rats in the other group lived together in a large rat park with lots of room to run around, play, and mate. Both rats were offered both morphine water and normal water. The caged rats took to morphine in a big way, while the park rats tried it but never really got addicted. When the researcher moved the caged addicted rats to the park, they weaned themselves off the morphine. In short, rats who could choose between park life and morphine chose the former. The researcher concluded that drug addiction is caused just as much by social and environmental factors as it is by addictive properties of substances themselves. Rats who enjoyed a good life were not as susceptible to morphine addiction as those who didn’t.

I think addiction probably lies in the least exciting place: somewhere in the middle. Substance addictions are not caused entirely by the substances, and behavioral addictions are not caused entirely by personal failings. Both kinds of addictions are caused by some mix of personal susceptibility, substance addictiveness, and environmental factors.


This is what Schüll argues for in this book. She tries to move the responsibility for gambling addictions from “personal failing” to “interaction between the person and the machine.”

She asks the question that every murder mystery detective asks: cui bono? Who benefits from the current state of affairs, where gambling addictions are largely considered personal failings? The casinos do. If addiction is the result of personal failings, then the responsibility for addiction lies with gamblers. Casinos are off the hook. They don’t have to change which machines they have, or how those machines work.

Vice industries, like the gambling and alcohol industries, are haunted by what happened to cigarettes. In the Western world, they went from being a commonly consumed indulgence to a barely tolerated health hazard. Even worse, Big Tobacco’s reputation lies in tatters because they knowingly sold a harmful product. No one wants to be the next Big Tobacco. Everyone is trying to avoid being seen as a purveyor of harmful products. Hence the American Gaming Association’s (AGA) insistence that “the problem is not in the products they abuse, but within the individuals.”

The AGA funds a lot of research into causes of addiction. In an ideal world, they hope to find a root cause for all kinds of addictions: gambling addictions, alcohol addictions, shopping addictions. That would prove that the gambling machines have no special magic. The same underlying cause motivates all addictions, and that underlying cause lies outside the machines. In the best case scenario, the underlying cause will be genetic. That way, the AGA can’t be blamed at all. If addictions are genetic, then would-be gamblers are ticking time bombs that enter the world waiting to get addicted to something, anything. Gambling machines are just the tool they happen to use sometimes.

While they wait for the research to find the genetic cause of addictions, casinos deal with addictions by putting more power in the hands of the gamblers. It’s a “you broke it, you fix it” approach. Some casinos use loyalty cards to identify problem gamblers, and then dispatch gambling addiction counselors to them for an impromptu counseling session. Others advertise loyalty cards that act as a “rationality prosthetic” by allowing gamblers to pre-program spending limits. Yet others offer educational materials about gambling addiction. Gambling magazines advise gamblers to establish a “401-G” to hold their gambling budget. In all these cases, the onus is on gambling addicts to monitor themselves for signs of addiction and then treat themselves if any exist. The gambling machines remain unchanged.

A game designer in the book calls these strategies “seatbelts that you can refuse to wear.” On one hand, casinos spend a lot of money buying machines that will entice the largest number of people to spend the most money over the longest period of time. On the other hand, they claim that gambling addictions are personal failings that can be resolved with more self-regulation. This is a more sophisticated version of the “stop hitting yourself” defense I used against my brother as a child.

And so we return to TikTok. TikTok creates videos that periodically encourage users to stop scrolling, and lets users set limits on their screen time. And yet, the blog post in which TikTok announced the latter feature includes a link (as of July 25, 2020) titled “TikTok trends to binge from June.” That’s the contradiction in a nutshell.

On one hand, TikTok engineers have created a supremely bingable app. It caters to interests I didn’t know I had. It curates an infinite ocean of content to find me exactly the videos that will make me say “just one more.” It is the next best thing to a dopamine drip. On the other hand, TikTok wants me to believe that the combination of my willpower and their timer is all I need to limit my usage.

I cannot help but think that TikTok, and other similar companies, are creating screen time tools as a first step in their journey down the path of arguing that “addictions are personal failings and overcoming them is a personal responsibility.” Screen time tools place the burden of managing addiction squarely on users, not on the companies that provide infinite addictive content. I’ll freely admit addictions are partly personal failings. It’s why I’ve deleted all addictive apps on my phone, why I’ve silenced all notifications, why I’ve been on a social media fast the last two weeks, why I monitor my screen time, and why I maintain constant vigilance against signs of increasing app usage. And yet, I wouldn’t need to fight so hard if my tormentors weren’t so strong, and getting stronger every day.


I buy Schüll’s argument that gambling machines are addictive by design. But I am left with a lot of questions about why gambling machines are so much more addictive than other, more virtuous, technology.

You might remember the gamification craze from the beginning of this decade. App creators were convinced that adding badges, randomness, and leveling up to any activity would make it irresistible. We were promised a new world where the power of gaming would be used for good. We would all chase after more steps with our Fitbits, more languages with Duolingo, and more math with Khan Academy. Move aside Portal and poker, there were new sheriffs in town.

And yet, despite following a lot of the same strategies that gambling machine designers did, those app creators never did create an army of self-improvement addicts. I haven’t heard any tales of someone losing his job because he was too busy getting more steps with his Fitbit, neglecting her marriage because she was too busy learning a new language on Duolingo, or dropping out of school to make more time for Khan Academy. Why is that? If designers can turn creaky slot machines into a multibillion dollar addictive product, why couldn’t they do the same for all these virtuous apps? Why can I, a person who gets addicted to apps fairly easily, not bring myself to spend more than ten minutes on Duolingo? Why are these apps still more broccoli than chocolate?

I think this is the biggest gap in Schüll’s theory. If designers optimized gambling machines for addictiveness, why can’t they do the same for these apps? If bad machines can be made addictive, then why can’t good machines?

I have a few hypotheses. First, maybe virtuous apps do create addictions, but the addicted population just isn’t getting noticed or counted yet. Second, maybe vices are just inherently more addictive than virtues. Third, maybe all designers worth their salt work for casinos, and virtuous apps are scraping the bottom of the barrel when they hire designers. The incompetent designers who work for virtuous apps just aren’t smart enough to create addictive products. I’m not sure which one of these hypotheses is correct, but I am glad to know that Schüll’s next book is about the rise of fitness trackers and other self-monitoring technology. I hope she will address this topic there.


The weakest parts of the book stem from the fact that the seed of this book was an academic thesis.

Because of that, the writing occasionally collapses into sleep inducing jargon: “I undertake what the philosopher of technology Don Ihde has alternately called a ‘phenomenology of human-technology’ and ‘materialist phenomenology.’ […] The idea of addiction as a coproduction greater than the sum of the parts from which it emerges resonates with the scientific understandings of addiction sketched above, and is especially fitting for a study of an addiction to interactive gambling technology.”

Also because of that, the book takes for granted that capitalism is synonymous with evil. While I agree with the book that one of capitalism’s failure modes is to give people too much of a good thing, I needed more persuasion to be convinced of other things the book blames capitalism for. Take, for example, its assertion that, to the extent that personal failings are responsible for excessive gambling, those personal failings are caused by late capitalism. Capitalism exploits and damages workers so much that they seek out the comfort of machines. But this theory doesn’t explain why the propensity to gamble is present in humans across space and time. Macau is a huge gambling destination, and all types of ancient myths talk about gods and people gambling to excess. Neither modern day China nor ancient Greece or India are hotbeds of late capitalism.


Machine gambling game designers have created games that induce the exact combination of regret and hope that makes gamblers play again. To do so, they have transformed slot machines, stuffing them with near misses and ever-lengthening odds. Gamblers are transfixed by these machines. More and more of them seek out the trance that the machines put them in. The lure of the machines is so strong that gamblers only stop when their money runs out. Supercharged machines and hypnotized gamblers together form gambling addictions. The gambling industry would like to absolve itself of responsibility for these addictions, but these addictions cannot be blamed solely on gamblers’ personal failings.

To maintain flow and conserve space, I couldn’t cover everything from the book in the review above. For example, two topics that I enjoyed reading about but didn’t talk about are (i) the design of machines other than slot machines and (ii) stories told by individual gamblers about their addictions. If that sounds interesting to you, check out the book: