This is Part 2 of a series called Designing Psychological Stickiness.

In each edition, I’m breaking down key psychological mechanisms companies harness to make their products super sticky multi-billion dollar generating machines.

Here’s a link to the first one:

• Designing Psychological Stickiness (Part 1)

In case you missed it, I dove into how massive companies like Facebook, Twitter, and TikTok use two powerful psychological concepts — Flow and Operant Conditioning — to drive adoption and heavy usage of their products.

In addition to social media and mobile gaming apps, I touched pretty heavily on slot machines; referencing a book called Addiction by Design to convey how certain game design mechanics and principles get people ‘hooked’.

Now, I’m returning to that subject from the standpoint of casino design. The real-world physical space, environment, and architecture surrounding slot machines in places like Las Vegas and Atlantic City.

At this point you may be wondering why this is relevant. As I highlighted in Designing Psychological Stickiness (Part 1), learnings and foundational principles from the gambling industry regularly cross-pollinate into other products and markets; particularly consumer experiences like social media, e-commerce, and mobile gaming.

Why? Psychological experience optimisation is key to monetising players effectively. Therefore, to maximise revenue, casinos have had to conduct a gazillion experiments. This is expensive (many billions of dollars) but cost-effective since gambling is such a lucrative business model.

Methodologies that work for casinos also work in other settings. Gambling is just one outlet emanating from similar consumer needs and desires.

The same is true of spatial design. This is becoming increasingly relevant as people spend ever more time immersed in apps, digital ecosystems, and virtual worlds.

Whilst design frameworks utilised by the gambling sector can be predatory, I’m not advocating that aspect of it.

Principally, they are fascinating from the standpoint of representing the productive output of a grand behavioural experiment involving hundreds of millions of subjects and tens of billions of dollars of investment.

It’s insightful to understand why they work since know-how from the gambling industry continues to permeate into others.

These design frameworks are also useful to inspire and guide initiatives in a variety of non-casino settings, both digital and real-world. Mainly as an instrument for increasing engagement in a healthy and balanced way, by designing experiences for compelling constructive not destructive behaviour.

Lessons From Vegas

The make-up of casino spaces has a huge psychological impact.

Architectural execution dramatically influences patron visit duration; which directly corresponds to TOD (time on device) playing slots and therefore coin-in (revenue).

There’s a direct relationship between the interior design of a casino and the interior state of ‘the zone’ — a mental state in which patrons transcend too for escape and relief. It helps direct, foster, and maintain it.

Easing players into the zone and keeping them there for as long as possible is a primary objective for casinos.

Tried and tested design principles maximise customer time and spend within a casino’s ecosystem; bouncing patrons around from one revenue-generating element to the next, like a gigantic human pinball machine.

The grand facades and showy theming of Vegas casinos seem to incept an unrealised appetite, but, this “experience-based” architecture doesn’t create needs and desires. It channels them, which is a critical distinction.

Whilst casinos might seem like blunt ‘build it and they will come’ monuments, the underlying nuances matter.

Casino owners have a relatively complex agenda to channel visitors through once they arrive. Each physical experience interaction — from entry to exit —needs to play a meaningful role in transitioning the customer onto the next. From awareness all of the way through to conversion and retention.

Successful casino design seamlessly ‘plugs into’ an existing psychological framework and set of perceptions.

It presents an attractive ‘highway of escapism’ for the prospect’s mind (the vehicle) to seamlessly merge onto — requiring few mental steps to get there.

To achieve this, casinos respond to popular modes and themes of escapism as part of a larger effort to guide those underlying needs and desires. Meeting the customer where they are mentally, not the other way around.

If you’ve seen films like Ocean’s Eleven and Casino, you’ll have a sense of the ‘tricks of the trade’ already — no clocks, no exit signs, no daylight, etc.

Natasha Dow Schüll summarised it well:

But, that’s just the tip of the iceberg.

The playbook for this is *a lot* more extensive. A pivotal moment was the opening of casino mogul Steve Wynn’s The Mirage in 1989. 👇

Prior to this, Las Vegas casinos were relatively small and “idiosyncratic structures” that served as relatively cost-effective studies in human behaviour.

They were more like ‘gambling halls’ than the behemoth resort buildings like The Mirage that followed.

To give you an idea, here’s the inside of the Golden Nugget, circa 1970s:

A successful pattern emerged during this pre-Mirage era, which can most aptly be characterised as the ‘dark intricate maze’ framework.

What’s that? Think of a maze of disorientating and dark narrow pathways festooned with dazzling slot machines.

More context:

The lucrative nature of these pre-1989 gambling establishments paved the way for something grander in nature.

Namely, The Mirage and its many gargantuan copycat creations.

Examples? Think The Venetian, Caesars, and the MGM Grand. These fastidiously crafted “total environments” promote self-abandon and escapism on an industrial scale. A world within a world — providing everything a customer needs — so they never have to leave.

Every brick, light, and stroke of paint was precisely chosen and positioned to lure patrons into the property. That part worked phenomenally well. Their external presence overshadowed everything that came before them —attracting millions of visitors through their doors annually.

But, they also applied a new and relatively untested approach to interior design. One totally unlike the proven formula that had come before. This unveiled some interesting data and differences of opinion. 👇

The Man Who Wrote The Book

In the year 2000, Bill Friedman — an expert in casino design — published a 630-page whopper of a book titled Designing Casinos to Dominate the Competition.

It was a ‘how to manual’ for highly productive casino interior design. And, the culmination of over two decades’ worth of research — mainly from first-hand experience operating in the industry as a casino manager and design consultant.

Published ten years after The Mirage and other copycat megaresorts opened, it uncomfortably highlighted that whilst their grand exterior design attracted more visitors than their dark maze ancestors, their interior design converted fewer of them into paying customers.

Bill also asserted that spatial design was more influential than anything else. Therefore, it should be the focal point to get right. Basically, he unsubtly suggested billions of dollars had been spent building visually impressive but not optimally productive megastructures.

Needless to say, it ruffled some feathers amongst the Vegas elite.

Whilst not “the only casino design template influential in the gambling industry today”, its foundational layers have been highly influential, recalibrating the way designers approach composing physical spaces, and are transferable to other industries.

What is most notable about Bill’s approach is not so much his design principles but the underlying framework that generates those principles.

For instance, he is critical of the architects and designers behind the post-1989 megaresorts for basing their plans on subjective preferences and not how the minds of prospects respond to those environments. You know, data.

Bill resolutely championed spatial design frameworks optimised for converting visitors into players.

Whilst the megaresort designers were experts at enticing visitors into and around their properties through huge pathways and attention-grabbing facades, Bill highlighted the role of designers doesn’t stop there. It extends up until the casinos’ ultimate objective — generating revenue.

The way he talks about casino design is reminiscent of a classic (albeit dated) sales funnel, often cited in digital marketing circles.

Spatial design is optimised around this flow:

Let’s break that down a bit.

• Awareness. This is the big, exciting facade. It grabs your attention.

• Interest. You’re walking in, subconsciously drawn by the luring pathways.

• Decision. You’ve spotted a game you fancy trying your luck on.

• Action. Bum down on seat, money goes in.

All of these phases must be calibrated optimally and flow seamlessly through design, one into the next, to maximise what Bill refers to as “player-to-visitor ratio”.

This is a key metric that tracks the conversion of visitors to paying gamblers. Otherwise, it’s like having a showy website that millions of people visit but rarely buy anything from.

Layered within this is an emphasis on psychology over utility. Utility is required to transport patrons into the interior casino space quickly, safely, and comfortably — that is rational.

But, the mechanism to convert visitors into paying players and keep them playing is largely irrational — meaning psychology must play a significant role.

Even outside of gambling, which is a potent example, prospect behaviour is heavily driven by psychology.

Thinking about spatial design with this scientifically measured ‘full-funnel’ approach, combined with the delicate balancing of utility with psychology at every step, leads to a productivity-first design mindset.

So, what are the design principles that underpin this?

Friedman’s Casino Design Principles

After 80+ casino field studies across two decades, Bill identified a few core design principles that lead to highly productive patron behaviour.

In addition to this, he is also a confessed (and recovered) “degenerate gambler” who identifies with the “motivations and experiences of players”.

Namely, that players seek an “inward focus into their own private domain, making them oblivious to anything around them”. This provided a true north direction with which to compose his design principles.

This is a critical aspect. And, applicable across most industries.

Data-driven design decisions are reactive, and therefore fundamentally limited by the quality of the experimental inputs that generate the data.

Understanding the intrinsic motivations of the prospect leads to a more productive experimental process by designing more closely aligned experiments in the first place. The alternative is ‘flying blind’ — guessing.

Next, I’ll jump into some of Bill’s key design principles.

Focussed Attention

This principle dictates that “every aspect of the environment should work to turn attention towards the [slot] machines, and keep it focussed there”.

In other words, spatial design should have a clearly defined objective. And, everything within it should ultimately navigate ‘users’ to that objective.

If there are too many competing objectives all treated equally (or disproportionately versus their value generation), productivity decreases.

For example, Bill says designing grand interiors (such as neo-classically decorated ceilings with elaborate paintings and fixtures) creates a ton of foot traffic, but it’s a low-yielding distraction that becomes a feature in and of itself. It will not function as a guidepost to the conversion goal, which is the only reason for its existence.

As a casino operator bluntly put it:

Every physical experiential aspect is governed by the Focussed Attention design principle. It’s all emcompassing.

From the architecture and general décor to the specific carpet patterns used, lightning intensity, aisle widths, background music, acoustics, and temperature regulation.

If any of these elements do not encourage patrons to accomplish the conversion objective, they are working against the interests of the casino.

Structured Chaos

This principle dictates the most optimal interior design layout sits delicately balanced between order and chaos — what Bill refers to as a “maze layout”.

Like a traditional maze, patrons navigate seemingly random and narrow aisles of slots without an obvious route to their end destination.

Unlike a traditional maze, their end destination is not one fixed point in the centre but numerous endpoints (slots) all around. And, fluid — moving from one machine to the next.

To much randomness and congestion, Bill argues, leads to patrons that “wander aimlessly and gaze blankly”. It creates disorientation and anxiety. Therefore, balance is needed.

An optimal ‘Friedman maze layout’ gives a sense of organised navigable structure to the chaotic twists and turns of the slots aisles.

To visualise this, imagine combining a maze with components of a symmetrical organised spatial layout (like a big government building) inserted in here and there. It feels kind of logical to navigate, but isn’t really.

This approach erases disorientation whilst maintaining the effects of getting ‘lost’ in a maze of tempting offers positioned along pre-defined routes (like Ikea).

Critically, the ‘Friedman maze layout’ engages visitors with slot machines straight away. Upon entering the casino floor, patrons enter the maze. There is no obvious or intuitive path to avoid or cut through it.

This is in stark contrast to the megaresort designs of the 90s, which featured “walkways that are too large, too open, or incongruent in their colouring. They are liable to induce players to move straight through a property without stepping off into its gaming areas”—a phenomenon Bill characterises as the “yellow-brick road effect”.

More on this next.

Flowing Pathways

This principle dictates pathways should be designed to prevent stalling, keeping movement flowing toward machines.

One key design trait to achieve this is the use of curves, not sharp turns.

Why?

Bill says casino patrons “resist perpendicular turning”.

It acts like a friction point, since “commitment is required to slow down and turn 90 degrees into a slot aisle.”

This principle extends from within the centre of the casino floor all of the way to the outside street, whether approaching by car or on foot. Curvy pathways and roads seamlessly ingest patrons into the inner machinery of the casino with minimal cognitive or physical friction.

Inside casinos, Bill says “passageways should keep twisting and turning through gradual, gentle curves and angles that smooth out the shifts in direction.”

Aisles and corridors “should narrow gradually, so walkers do not notice the approaching transition until they suddenly find themselves immersed in the intimate worlds of gambling action”.

This combination of wide open outside pathways that gradually meander and narrow into the centre of the casino is analogous to entering a river by its estuary and eventually arriving at its source. Transitioning a mass of people from a broad space with little preoccupation into a condensed one that offers many.

Progressive Discovery

This principle dictates patrons “can only see a short distance ahead to the items directly in front of them.” They cannot see very far in any direction—ahead, sideways, or overhead.

The psychological effect of this is progressive discovery. Players are ever curious to walk a little further, lured in by the prospect of discovering what is beyond the next row of machines or bend—their favourite slot, a high jackpot, a quiet recess, etc.

A parallel can be drawn between this and the act of gambling itself.

Bill advises designers to offer ‘hints’ and cues at what lay beyond. Kind of like a teaser, without giving too much away. This amplifies the effect.

An example of this is a tunnel leading to the front entrance of Caesars Palace. A band of lights was installed that flashed in a “slow, sequential pattern, subliminally creating the same effect that is obvious to pilots approaching airport runways.”

The lights gave customers a focal point that led them to the casino entrance. Before, people often jammed up inside the tunnel without a clear sense of direction.

Space Elimination

This principle dictates patrons should have small and constricted spaces to ‘hideaway’ in—alcoves, corners, recesses, and other nooks of privacy.

Slot machines placed in these locations, it turns out, get played the most. But, why?

Bill says big open spaces dissipate energy and cause anxiety—such as excessive visible depth, excess horizontal space, and large voids created by high ceilings. This burdens a customer’s ability to remain in the zone. Player’s don’t want to feel “exposed”.

Bill doubles down on this by explaining players “want to be isolated in their own private, intimate world from the surrounding hubbub that attracted them in the first place”. This is key for players to get in the ‘zone’ and stay there for long periods without interruption.

To achieve this, the casino floor must be segmented into compact areas isolated from one another. Rows of slot machines are strategically positioned to create a maze-like effect, creating small —tucked away— zones that make a player’s world small.

“This psychologically separates the area from the rest of the casino” — it fosters a sense of privacy, protection, concentration, and control.

Modulating Affect

The last principle I’m covering today addresses the role of the casino environment once a conversion event has taken place. That is, when a patron has sat down at a machine to play.

In this scenario, it is key for the machine itself to take over as the primary form of psychological guidance and motivation. But, the casino environment still plays a role in the background.

The principle of Modulating Affect helps keep players content through atmospherics, noise, smell, light, temperature, acoustics, and everything else that the senses of the human body absorb consciously or subconsciously. All of this must be calibrated appropriately to keep players in ‘the zone’.

The consistent theme within Bills guidance on this principle is ‘low volume’. Not just decibels, but everything. All casino environment stimuli should be calm, pleasing, and easy to digest across all senses. Like a security blanket that demands nothing of the patron.

Within the casino industry, the tolerable bandwidths and playbook for conducive stimuli has been established and well-known for a long-time. There’s an entire supporting industry of suppliers who offer everything a casino operator might need to propagate a soothing environment.

Despite all this, it’s still an evolving science. An (old) study from 1995 particularly piques my interest in this field of inquiry — Effects of Ambient Odors on Slot-Machine usage in a Las Vegas Casino.

It found that slot revenue increased by 45% in a casino floor area doused with Pleasing Odor A versus remaining the same in another casino floor area doused in Pleasing Odor B.

Whilst I don’t think that number would hold up over the long-term or with scale, it is indicative of the ability to wield environmental stimuli as a lever to increase player propensity to engage with slot machines. Even an increase of a few percent would be very meaningful, particularly for one stimuli alone.

Due to this, Bill is particularly bothered by any environmental element that expends energy from human “perceptual systems” (like loud music) or demands cognitive load (like conflicting design cues).

Such “noxious excesses”, he characterises, act like an abrasive substance on the playing customers’ energy, focus, and sense of escape.

Whilst a grossly imbalanced set of environmental stimuli may deter customers from continuing their playing sessions relatively quickly, it is the subtle calibration of stimuli at a pretty nuanced level that can encourage players to play for eight hours versus seven. Or, nine hours versus six, etc.

The effects of even slightly imbalanced stimuli magnify over long-duration play sessions, where casino owners earn a significant fraction of their gambling revenue.

A barely perceptible discomfort at the start of a long play session gradually amplifies into a major irritant by the end. Something as seemingly innocuous as music played at a few decibels too high can eventually induce a play-stopping trigger.

It’s analogous to sitting on a long-haul flight. At the start you barely notice the droning engines, dry air, and hard seats. Eight hours in, those irritants have gone beyond perceptible to plain uncomfortable.

That’s it for today. I’ll be back with Part 3 later.

Martin 👋

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