The act of gambling may be as crucial to the buzz as the winning.
No one likes to lose - even pathological gamblers. And yet they keep on betting. If the house always wins, why roll the dice again? People addicted to gambling frequently report that, despite losses stacking up, the buzz keeps bringing them back to the card table or slot machine.

"I wanted to gamble all the time," one former addict recalled to Scientific American in 2013. "I loved it — I loved that high I felt."

And recently, one Wall Street executive admitted defrauding family, friends and others out of $100 million to feed his habit.

"It was just a way for me to get money to feed a gambling addiction," he told the court.

But if someone is ultimately losing money - perhaps even losing their job or house as a result of nursing their addiction - how can that high possibly outweigh the sacrifices?

The first thing to note is that people don't just gamble for the prospect of winning. Mark Griffiths, a psychologist at Nottingham Trent University who specialises in behavioural addictions points out that gamblers list a wide range of motivations for their habit.

In a survey of 5,500 gamblers, the prospect of the chance to "win big money" was the strongest factor. But it was followed closely by "because it's fun" and "because it's exciting".

"Even when you're losing while you're gambling, your body is still producing adrenalin and endorphins," he says.

"People are buying entertainment."

This is backed up by a 2009 study by researchers from the University of Stanford in California, who found that around 92% of people had "loss thresholds" below which they would not go. However, the fact that they lost money overall after visiting a casino, for example, did not necessarily impact their overall enjoyment of the experience.

"People seem to be satisfied with relatively small wins, and will tolerate even smaller losses," said co-author Sridhar Narayanan at the time. "They tend to be conscious that, in the long run, they are more likely to lose than win."

And losing could actually, momentarily at least, boost the positive response to a win. This is because of how gamblers' expectations of winning change during a losing streak.

Robb Rutledge, a neuroscientist at University College, London, and his colleagues performed an experiment with 26 subjects whose brains were scanned while they made a series of selections, each of which could result in either a certain outcome or an uncertain one - a gamble. Participants were also asked to rate their sense of happiness after every second or third go. Plus, a similar experiment - without the brain scanning - was carried out by over 18,000 participants via a smartphone app, The Great Brain Experiment.

Among various interesting findings, the team discovered that when participants had a lower expectation that they would win, their response to winning equal rewards was elevated. This was evidenced both by subjects' own reporting of how happy they felt and the data from the fMRI scans. These scans revealed increased activity in an area of the brain associated with dopamine neurons. Dopamine, a complex neurotransmitter, could in this case be linked to changes in emotional state.

"If people lose a bunch and that lowers their expectations, that will increase how happy they are when they finally do win," says Rutledge.

This alone is tantalising.

"If a couple of bad things in a row happen to you and your expectations go down - but then you actually get some good outcomes, you'll probably be happier," he explains.

Some machines may be designed to actively entice us to gamble with the very colours they use.
"Though you should probably walk away at that point."

But are devices like gambling machines actively manipulative as well? Griffiths has written about the cues that electronic gaming machines give to players. Much is still unknown about how their design impacts player behaviour, but, for example, many machines and casinos use red and similar colours - considered more arousing. Then there is the role of sound. Griffiths wonders whether the taunts of a common machine referencing The Simpsons has an antagonistic effect on players.

When a player loses, for instance, the character Mr Smithers might declare, "You're fired!"

"In line with hypotheses supporting frustration theory and cognitive regret, this might make the electronic gaming machine more enticing," writes Griffiths in one paper.

One key factor in how addictive any kind of gambling might be is how frequently players can place bets. Because the availability of opportunities to gamble is linked with the level of problem gambling in a given community, Griffiths argues that it is the number of potential rewards - not actual rewards or even the type of betting - that drives pathological gamblers.

Games and machines are also often designed to keep players interested by offering substitute rewards, like additional credit or - after a loss - the possibility of winning bigger than usual next time.

"If you build in lots of little rewards that are not necessarily financial it will keep people responding," says Griffiths

And, interestingly, there are cases in which gamblers might try to develop a "pseudo-skill" as a sort of justification for targeting those potential rewards. Griffiths gives the example of UK gaming machines which are designed with adaptive logic that means they might pay out more than they take from customers during a certain period, after which they will revert to a less generous system. This means that some players try to seek out (or "skim") machines which have been holding back jackpots, in the hope of being there when the tide turns.

All of this contributes to the idea that much of gambling isn't about winning at all. It's about the process of betting itself - and all the attendant factors that make that enjoyable. While pathological gambling can't be explained so simply - there are often many reasons why an addiction might develop in a person - it's certainly interesting to explore how the excitement of a flutter might be tied to the style and structure of whatever game is being played.

And even when it's not a problematic obsession, gambling still seems to entertain those who go home with empty pockets. Should you put it all on red or black? Well, maybe it doesn't matter.