They aren't worth any money and you can't win them.

 They can't make you any money, and they're completely free to play until they aren't.

Social casino games are web-based or mobile apps that let you gamble without any expectation of winning.

Some of the most popular games are poker, slots and bingo.

You would get a certain amount of virtual coins when you start a game like slot machines. You'll have to pay if you run low and you want to continue playing.

Australia bans online gambling. Social casino games can't be won, so they aren't gambling. It is also less regulated than real gambling.

Each year, the global social casino market generates billions of dollars in revenue. These gambling simulators can prove to be as harmful as real gambling.

A Mackay woman was arrested last month after she stole nearly $1 million for her social casino addiction. While a Perth man boasted of spending $800 in minutes to play a virtual slot machine, another Mackay woman was sent to jail.

You can't win real money on these games and you can't cash in. But how can you get addicted to these games?

It's not just about the money

Sally Gainsbury, director of Sydney University's Gambling Treatment and Research Clinic says gambling has a universal appeal. She believes that it is risk-taking for rewards.

She states that even though the reward may not be material in monetary terms, it still has value to the user.

Even though you will never win big in a social casino game you can still feel like you're getting a prize. You may find it difficult to stop playing once you run out virtual chips.

Dr Gainsbury says that the sounds and lights in these games are very similar and evocative of a gambling environment. "They give you the same rush dopamine...and that's exactly what people are paying for," Dr Gainsbury said.

Anna Lembke, a dopamine expert has shared her experience with All In The Mind Podcast that dopamine makes you feel happy and super high. So we search for the activities and substances that provide that feeling.

She said, "When we are able to have fun, such as eating chocolate or having sex with a friend, our brains release the chemical Dopamine in what's known as the reward path."

"It is a specific circuit in your brain that processes pleasure, reward."

However, it can leave us wanting more.

When we see something that reminds our favourite social casino games, such as an advertisement or a notification to continue playing, our brain releases small amounts of dopamine.

Dr Lembke states that even though you are not engaging in the behavior, just being reminded releases dopamine. The mini dopamine deficiency state is followed by craving. casino slots