It All Started With… The History of Blackjack, or How 21 Became Our Favourite Number in the Casino

9 min readJun 22, 2021

It all started with… the series that explains the beginnings of gambling powered by Betiton™

Welcome to the second entry of our series ‘It All Started With…’, which is a series on the history of casino games. In this entry, we’ll be turning our gaze towards the history of blackjack.

We’ll first be investigating the fascinating history behind blackjack, then we’ll be giving our thoughts on how it became so popular and what the future holds for this great game!

‘It all started with a card game somewhere in Europe…’

So, if you ever wondered how this card game become so popular, or where it come from, or what the reason behind the particular number of 21 is, or if you’re simply curious about the answers, then read on to find out!

The Obscure Origins of One of the World’s Most Popular Card Games

Whilst the true origins of blackjack are shrouded in mystery, there are some things that we actually know about the game. We know, firstly, that blackjack originated from another game, one whose beginnings are truly unknown to us. This game was known by various names, namely, Twenty-One, Vingt-Un, Vingt-et-Un, and so on.

There are many theories as to where Twenty-One might have originated from. The first is a theory that Twenty-One is a descendent of a gambling game played by the Romans — but it doesn’t hold much water. The theory goes that the Romans used wooden blocks with numbers on them to play a game similar to Twenty-One.

blackjack cards next to stacked casino chips
Image by Michael Brasuela from Pixabay

Whilst the theory seems plausible thanks to the Romans’ penchant for gambling — to the point of being almost an obsession — no evidence of such a game has been uncovered. Much more credible theories don’t go as far back as ancient Rome, but settle on the 17th century (mostly, however, due to a paucity of evidence).

Spanish Dictionaries and Fictional Cheats: The First Mentions of Twenty-One

The first written mention of the game of Twenty-One can be found in a 17th-century dictionary compiled by Sebastián de Covarrubias. The dictionary — which was published in 1611 and titled Tesoro de la lengua castellana o española (Treasury of the Castilian or Spanish Language) — mentions the game of Ventiuno (Twenty-One) under the entry ‘carta’ (card).

Not long after, the word appears once again in a short story written by Miguel de Cervantes, the famed author of the Spanish novel Don Quixote. Cervantes was an avid gambler himself, so it’s no surprise that the author would write a story centred around one of his favourite things.

The short story — which was written as part of a collection of stories titled Novelas ejemplares (Exemplary Novels) — is titled ‘Rinconete y Cortadillo’ and follows the adventures of two characters who make their way to Seville to join a guild of thieves. The characters end up swindling people by cheating at the game Veintiuna.

In the story, the characters also describe how to play the game: according to the cheats, the objective of the game is to reach 21 without going over it, and the ace is worth either 1 or 11. This is uncannily identical to the game that’s played in casinos today, which means that the game has kept the same objective for over 400 years.

As to where Ventiuno might have come about, that’s as good as anyone’s guess. However, it’s theorised that it might have been developed from earlier table games, such as the Italian Sette e mezzo (Seven and a Half), the French Quinze (Fifteen), and especially the Spanish Trente-un (Thirty-One).

These are all games that have a similar objective to Twenty-One, that is: reach a certain score without going over it, or as close as possible to the score. At the same time, if you didn’t manage to reach the particular score, your hand needed to have a higher value than your opponent to win.

From Europe to America: How Twenty-One Became Blackjack

Wherever the game came from exactly, we at least know where it went next: to America. Vingt-Un was extremely popular in France between the 17th and 18th centuries, so it was only natural for French colonists to bring the game with them to the colonies in North America.

The game, naturally, became extremely popular in America. In fact, it become a nearly omnipresent game in American gaming houses, especially in New Orleans, where gambling was rampant. However, at that time, the game was still known as ‘Twenty-One’ or ‘Vingt-Un’.

It was some time during the 20th century that the game came to be known as ‘blackjack’ and even here, the origin of the change in the name of the game is unclear. A popular theory is that ‘blackjack’ is the name of a bonus that has long went out of fashion.

The theory goes that gambling houses needed a way to incentivise players to play Twenty-One at their tables and so they offered a bonus bet known as ‘blackjack’. The bonus bet required players to receive a hand consisting of an ace and a black jack (jack of spades or clubs), and they’ll be rewarded with a ten-to-one payout.

However, card game historian Thierry Depaulis has revealed that this theory is deeply flawed: firstly, jacks have no special role in blackjack, so it’s weird that they would form part of such a bonus bet. Secondly, bonuses such as this would give the player a significant advantage over the house, thus making no sense for the house to offer it. And, lastly, there is no real evidence that such a bonus bet has ever existed.

Instead, Depaulis has found many references to the game of blackjack in connection with the Klondike Gold Rush, which was a migration of gold prospectors to the Klondike region of Canada. According to these references, the name ‘blackjack’ must have been coined by the prospectors playing Twenty-One in Canada.

This is where it gets interesting, however: ‘blackjack’ as a word has many meanings, one of which is a popular name for a particular kind of zinc ore (which is technically known as ‘sphalerite’). This ore often had the form of black crystals, which explains how it received the name ‘blackjack’.

Interestingly enough, there is a saying in Cornwall that mentions this ore, which goes: ‘Black Jack rides a good horse’. In other words, when sphalerite is found, it’s often an indication of a rich source of ore. This would suggest, then, that the word ‘blackjack’ became miners’ slang for a favourable situation or a lucky stroke.

Thus, it might have been the case that the best possible combination in Twenty-One — which is also known as a ‘natural’ and which instantly wins you the game with the first 2 cards — was called ‘blackjack’ by the miners, due to its association with good luck. Naturally, the name came to be extended to refer to the game, the same way the game was called ‘Twenty-One’ in reference to the score needed to win.

players around a long table playing blackjack
Photo by JT on Unsplash

Why Was the Game of Blackjack Invented?

As is the case with every other form of gambling game, blackjack was likely ‘invented’ as a way of passing the time. When thinking of ‘why’ these games were created, we have to bear in mind that gambling has always been a very popular and common pastime, even in the past.

The long history of gambling and card games means that new rules for playing with cards would naturally spring up whilst at the same time old rules would die out — much in the same way as language, where new words come and old words go. Rules would have been added on to already existing games, creating new variations of established games or a totally new game.

Otherwise, rules that have nothing to do with pre-existing card games would be imported into a card game. For instance, card game historian and scholar David Parlett is of the opinion that the rules for blackjack-like games may have been based off the rules of dice games rather than those of previous card games.

Furthermore, and as we saw before, different countries had different rules for similar games, which means that changes also occurred as games and playing cards moved around geographically.

So, Where Does That Leave Blackjack?

Of course, blackjack wasn’t invented per se — not like the microwave, the telephone, or the internet were invented. Blackjack comes down to us as the result of decades of evolution and gradual modifications of a particular card game or concept. As such, since blackjack wasn’t invented by a single person, it’s doubly difficult to pinpoint its true origin.

It could have been created by soldiers in between campaigns; by a group of friends wanting to play an interesting new game of their own invention; by workers wishing to pass the time during their hours when there wasn’t much to do; or by an establishment owner wishing to create an interesting new game to attract patrons; or, thanks to its long history, the game could have been invented and reinvented many times over!

In fact, playing cards have been around since the 10th century, with their first appearance in Europe being in the 1370s. Moreover, the first documented card game in Europe was played in Germany in the 1420s and the first written mention of Trente-un is from 1440, which proves the long history of card games in Europe.

Overall, it’s nearly impossible to say how blackjack was exactly created. It could have been a simplified version of Trente-un, or an enhanced variant of either Sette e mezzo or Quinze. We can never really know for sure, but at least, we can appreciate blackjack for what it is!

How Did the Game of Blackjack Become So Popular?

There are many reasons as to why blackjack became as popular as it did. By far, the biggest reason is its ease of play: blackjack is not a very complicated game and can be quite easily picked up by anyone. There aren’t many rules that need to be remembered and the ‘points system’ is also fairly intuitive.

Moreover, the fact that the game only requires a pack of cards to be played helps a lot as anyone could play it anywhere. In fact, for much of its ‘lifetime’, blackjack was played outside of any legalised gambling establishment. Even nowadays, blackjack is played outside of the casino.

Finally, blackjack is a very fast-paced game: in fact, a round of blackjack can be finished in well under a minute and another one can be played immediately afterwards. It’s this combination of ‘simplicity’ and rapid, exhilarating play that must have made blackjack as popular as it is.

The Future of Blackjack

It’s clear to see that blackjack’s heyday is far from being over and its popularity might actually increase even further. In the world of online gaming and casinos, game providers are constantly thinking of ways to innovate the game. In fact, recently there have been many minor additions to the game that changed the way it’s played entirely.

For example, simply by changing when the dealer hits and stands, the game affords a different gameplay each time. Moreover, developers like Evolution Gaming have created a number of different blackjack games by adding interesting rules, side bets, or by removing certain cards to spice up the game.


It all started with a card game somewhere in Europe that kept being modified as it moved from country to country, from continent to continent. Whether blackjack developed from Trente-un, Sette e mezzo, or Quinze is unclear; what’s clear is that blackjack’s history can be traced to at least the early 17th century.

From there, it seems that the game’s popularity never waned but quite the opposite, it continued increasing until it reached today’s extremely high levels of popularity. In fact, it can be said with confidence that blackjack is the most popular casino card game of all, even beating out baccarat and poker.

With so many things going for it, it’s hard for any other card game to dethrone blackjack from its place at the top of popularity chain. If anything, blackjack will continue to gain popularity, especially as it continues being developed to include a number of interesting variations and rules.

In the meantime, join us on our next entry where we’ll be going into the history of another highly popular casino game!

Other Articles in Our Series It All Started With…

Curious to know more about the history of gambling? You can find out more by reading our other articles in our series It All Started With… which you can find below:




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