Most of us have played games like poker and blackjack with friends. Up to a point, these games can be great fun. Unlike other forms of play, however, gambling taps into a side of the human mind that encourages damaging behavior, often to the point that many people have stories about friends or relatives who have lost everything to gambling.

Video gambling describes slot machines and the other electronic machines found in most casinos. Vastly profitable— generating up to 70% of casino revenues in the U.S.—these machines are also examples of experiences designed to manipulate user behavior.

The way gambling companies justify their revenue source is intriguing: they promote it as social and fun while also claiming to help people with gambling problems. Behind the scenes, however, they engage in all kinds of “optimizations” that encourage gamblers to spend and play more without stopping or burning out.

How do I know this? I have something to confess.

Early in my career I was one of those “dark side” UX designers at a video gambling company. I’m not proud of it, but I learned a lot about the psychological techniques they use. People often say that gambling companies are the masters of the dark side of UX and gamification, but not many of us know the details. I do, and I’m going to share them with you in this article, which supports a presentation of the same name that I've given on the topic.

From Seduction to Deception

As with many relationships, gambling starts with a seduction phase. The experience of walking into a casino is carefully crafted to deliver the promise of fun, pleasure, and riches using a heady combination of lights, music, and fantasy. It’s no accident that the gambling machines are branded with themes from popular culture: they are designed to make you feel comfortable, appeal to you sexually, or provide aspirations to a new, higher social status. You may find it hard to believe but this stuff really works.

In-Game Patterns

Video gambling machines are designed to be easy to walk-up to and play. The learning curve is minimal. Once they’ve got you playing then a number of “dark patterns”—user interfaces designed to trick—are applied.

A disparity between perceived and real odds

The user interfaces on many machines hark to the old days with a physical lever that you pull and dials that spin around, alluding to the idea of natural randomness: like rolling dice or picking a card from a shuffled deck. In fact, the machine runs on software that tells the dials exactly how to spin and where to stop.

Although random number generators are used, the bounds of the randomness are predetermined, and the payout rate is set in favor of the house by about 10%. What’s fascinating is that many casinos make this fact public on large signs (e.g. “The payout rate on these machines is 90%! Play now!”). Gamblers continue to play, in an attempt to beat or “game” a system that has been specifically designed from the ground-up to game them.

The gambler’s reasoning is that although the house takes 90% of the money put in, this figure is an average across the entire population of players and, as an individual, they still stand to win a large amount. Of course, all gambling odds are stacked in favor of the house. What’s fascinating about video gambling is the extent to which this is engineered. For example, slot machines are often networked, not just within single casinos but across multiple casinos, allowing payouts to be adjusted between games to meet profit margins.

High bet buttons are prominent, low bet buttons are hidden

All UX designers know that it’s important to show a clear and prominent call-to-action to convert your business needs. This is why the “create account” button on a website tends to be big, and the “delete account” button tends to be a small text link tucked away deep in the settings page.

The exact same principle is used in video gambling machines. The big prominent buttons are always the ones that encourage you to spend more and continue gambling. The buttons that allow more sensible behavior tend to be just a little smaller or harder to find. When averaged over millions of players, these small design tweaks have a big impact.

The game’s rules are so clear that you do not need to worry about learning curves. The thrill is there and the jackpot is poised to make you rich—why shouldn’t you play longer? Deception goes along with dark patterns, unnoticed and exploiting psychological resorts of your mind.

Here are some examples.

    • Interface is designed deliberately so you spend longer looking for the low bet button (when it exists) or the cash out button. Conversely, betting buttons and their placement make very easy to keep playing or gamble it all.
    • You end up not noticing how many times you’ve lost because you “win” a few small or medium prizes as you play, but you’ve still lost more money than what you’ve won back.
    • Near misses”—one of the better-known tricks that makes you feel like you’ve just missed out on a win. This excitement causes your brain to release dopamine, creating a natural high. This is similar to the concept of “perceived scarcity”—also used in marketing to convince consumers that an offer is limited and they must buy it as soon as possible.

  • Changing the currency from Dollars to credits hides from you the real money you’re spending. By giving you control with the bet and the value of the credit, you lose your perception of money. Now it is just time in the machine: more credits equals longer play. Another careful ploy used is when a prize is won the sound of clinking coins is played to make you feel like you’ve won real money, not just credits.

The Grey Zone Is Not Flow

What started with seduction and a promise of riches has slowly become a relationship based on deception. A gambler’s state of mind is far from Csikszentmihalyi’s flow, in which an activity produces an experience so gratifying that people are willing to perform it for its own sake. When gambler’s play video gambling machines, they want to get in what they call “the zone” because they can forget the rest of the world. This is different from the flow, as they do not experience clarity and do not need a motivation to achieve any goal. It’s pure escapism.

Natasha Schull explains “the zone” in her recently published book Addiction By Design. She interviews true gamblers to explain their experiences losing their sense of time in front of the machine: minutes turn into hours, hours into days. The “Auto” button which allows not pressing any buttons at all to keep playing is perfect for this purpose—pushing the user into gambling in a more automatized way.

When gamblers are in the zone they become a money making machine. But these companies and casinos don’t just stop with the machines. In the early ‘00s the Harrah’s casino in Las Vegas hired a young PhD in economics named Gary Loveman who applied data mining to the gambling information system and created a loyalty program with massive success. Analyzing the data in real-time allowed seeing which users could play longer and what game and casino floor design changes were more profitable. Other companies copied the method and user research converted gamblers into figures that could be improved by handing out rewards.

Dark Design

Last year, information architecture and UX guru Louis Rosenfeld asserted in a tweet that “User experience is a strain of 21st century humanism.” Think about what UX involves as a discipline: knowing the user needs, coordinating with engineering, and understanding the market. You may not find any other profession with as many inputs from different people and different areas. But an ethical dimension should be fundamental.

The elements of the video gambling experience are like the elements of any other webpage or software: they are designed to match the user needs and they align with the products’ strategy. The problem with video gambling is that user needs are swallowed up by a compulsion to continue using the product, a compulsion that the product is designed to deepen and exploit. These elements are continually enhanced with iterated quantitative research to further optimize the experience, sucking the gamblers further in.

Aligning business needs with user needs can be a delicate balance, but video gambling raises the question of whether or not honesty and integrity should always be the overriding principle in any design choice. In my opinion, optimizing a form or payment system is one thing, but tricking a user into spending more money is another. What do you think?


Image of hand pressing play courtesy Shutterstock


What is the purpose of UX? To keep the user engaged. Why does the developer seek maximum user engagement? To monetize their application. Whether it's buying things we don't need with encouragement from Amazon or doubling down on a pair of jacks, UX aims to optimize the monetize. When designed to appeal to our self-damaging impulses there is no "dark" or "light" option for determining the ethics of UX design. Gambling is not the issue here: The issue is user manipulation. And when (as with Amazon and many others) the user's transactional history is analyzed for the purpose of presenting them with buying opportunities to which they are most vulnerable, there's no solace in claiming the ethical high ground over gambling. You're down there in the muck with the offshore charlatans by buying into the most cynical determinant of success: Never give a sucker an even break.

I do not like the slot machine gambling, but if I did, the dark UI you describe would be exactly what I wanted. Why should I prefer smaller bets? That would make me feel not a James Bond type playing in a true Casino but a poor miserable guy never free from the necessity to count every hard earned cent. Without near misses, why not just roll dice at home? Do not worry Marc, you did nothing wrong. Profits are naturally higher when you service customers better.

You didn't mention the target group that the gambling and games industry prefer the most: the careful players who consistently play a few hundred per week and who bring in the constant revenue. They don't want the addicted players who, in addition to giving the industry a bad name, are a minority and bring in very sporadic revenue.

The gambling industry must follow fairly strict rules, but the software games industry doesn't. Even though they do the same thing: get players hooked into consistent use. I think the current games and entertainment software industry is worse than gambling; they're allowed to target children.

I would argue that UX practitioners are hired to create deception for the sake of profit on a wide range of industries, not just gambling. I think every project we work on should be inspected through the lens of morality and ethics because we are often the only representative of the customer/user/public while it is being made.

A very interesting and controversial topic, thanks.
Someone much more talented than me once said, "There is nothing either good or bad, but thinking makes it so."

Perhaps it's easier on the conscience to believe this to be so - that we're all capable of making our own life choices, and if we want to indulge, then that's our look-out. And hey, we all have a living to make and if you don't optimise the interface, there's plenty of other people who will. Right?
The reality is much murkier of course.

What I would say is that if you've earned your UX spurs by employing dark patterns to 'encourage' people to add that insurance to their flight, or hinder them leaving a service, or indulge in behaviour which is personally destructive - then why not use your UX skills to perform good in the world?!

And there's huge scope for UX (and 'Design' as a whole of course) to deploy Design Thinking to solve many many social and environmental problems.

If you want to know more (and if I know UX people, then I think you will!) then check out Wicked Problems by Jon Kolko:
Get involved in design problems WORTH solving! :)

I think it is a matter of choice as designers, like Philip says. We do not relate to people directly but through visuals and technology. And it is through the products we involve in our jobs that we support business goals,...This can be fair. It is how society works. But, what if the business has more information about the user and use it to take advantage of his helpless situation? The exchange between the company and the user becomes totally asymetrical. UX becomes a refinated way to kidnap somebody. But this also exists in "check out" processes in some e-commerces (shopaholics are not different from ludopaths),...Technology amplifies. Users dive into a sea of other people's intentionalities and requests.

No matter what you do for a living you have to ask yourself whether this creates a benefit for others or not.

In respect to your article, UX designers who apply their knowledge to gambling are not much different from ad agencies who create advertising to entice people to buy a product / service. At the end of the day both sell a dream.

When you buy Coke / Levi's / Apple, you don't just buy a product, you buy into a life style that has been crafted for the brand.

When gambling you're buying into the dream that you might become rich. Using dark patterns to lure more people into that dream is just like marketing.

The main difference is that in the product / service world, you at least get something in return for your money.

In gambling, the casino just takes the money and promises you that might make more back than you invest. But that's a dream ...

Ultimately it's up to the individual whether he chooses to indulge in that dream or not. And as UX designers it's our choice whether we want to support an industry like gambling in the same way we choose to work for financial services, tobacco, alcohol, weapons manufacturers or online retailers.

It's all about choice.

As in many other jobs, you can use your skills to make a better world/web or to your own profit.

But I want to be optimistic ; one does not become UX designer in order to manipulate people but to bring them better and richer experiences.

Hi Marc,
thank you very much for this article. I am glad somebody is starting to talk about the dark side of our work.

I strongly believe that we must raise ethical questions about our practice.
When I talk with other people about it, the main argument against my concerns is that people are not robots and even a well designed interface/experience cannot force users to do what they don't want to. Obviously people are not robot ,of course, but we must take into account that each user is different and this is a sensible area and a disease (the ludomania) is involved.
I think that we have responsibility for that since our work is to make the experience seamless, attractive, enjoyable and effortless.

I am curious what other colleagues think about it...