This is 99% invisible. I'm Roman Mars.

Americans have always had an uneasy relationship with gambling.

To circumvent anti-gambling laws in the U.S.

Early slot machines masqueraded as vending machines.

Or a trade machine, as they were called.

And the symbols on the machine had to obscure its true intent.

So you'd have these fruit symbols of cherries and lemons and oranges on the

reels and they would offer prizes like chewing gum or other treats that you would then

have to redeem for cash.

Like tickets and Chuck E. Cheese.

So it was almost like laundering it back into money.

Many slot machines have retained the fruit symbols to this day.

Heck in the UK, they're actually called fruit machines because of this.

So that is a carryover from that era.

The near universal bar symbol, which I always thought represented stacks of bars of gold has a similar origin.

The bar symbol is actually based on the logo of the Bell Fruit Gum company.

I'm talking with the Dow Schull. My name is Natasha Dow Schull and I'm an associate professor at MIT and the title of my book is Addiction by Design.

All about machine gambling in Las Vegas. And the title of my book is Addiction by Design.

All about machine gambling in Las Vegas.

You can probably picture a slot machine pretty easily.

The image we have that we carry around in our minds of the slot machine.

It's pretty much the same machine that came out in 1895.

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