Background reading
Some genuinely interesting facts about casino games
These are facts that are verifiable, timeless and — at least in our view — genuinely worth knowing. Nothing invented or embellished; all of it from documented historical and mathematical record.
Playing Cards
Playing cards originated in Tang Dynasty China
The earliest references to playing cards appear in China during the 9th century, during the Tang Dynasty. The precise form of the games played with them isn't fully documented, but the technology — printed cards used for games — spread westward through the Middle East and arrived in Europe by the late 14th century.
The four suits in a standard deck have different origins in different countries
The suits we know today — hearts, diamonds, clubs and spades — are the French version, which became dominant partly because French cards were cheaper to produce (suits were printed as single colours rather than the more labour-intensive German designs). German-suited decks used acorns, leaves, hearts and bells. Spanish and Italian suits used cups, coins, swords and clubs.
A standard 52-card deck can be arranged in more ways than there are atoms on Earth
The number of distinct arrangements (permutations) of a 52-card deck is 52 factorial — roughly 8 × 10⁶⁷. That number is so large that any specific arrangement you shuffle to has almost certainly never existed before and will almost certainly never exist again. For reference, the estimated number of atoms in the observable universe is around 10⁸⁰.
Roulette
The roulette wheel was originally designed as a perpetual motion machine
Blaise Pascal, the 17th-century French mathematician, developed an early version of the roulette mechanism in 1655 while attempting to create a perpetual motion device. The gambling use came later. The zero pocket — the green space that gives the house its edge — was added to the European wheel in the 1840s by the Blanc brothers in Bad Homburg.
All the numbers on a roulette wheel add up to 666
The numbers 1 through 36 on a standard roulette wheel sum to 666. Whether this influenced the nickname 'the devil's wheel' or the name came first isn't entirely clear, but the arithmetic is straightforwardly true.
American and European roulette have different house edges
European roulette has a single zero, giving a house edge of approximately 2.7% on even-money bets. American roulette adds a double-zero pocket, raising the house edge on those same bets to about 5.26%. The two-zero layout was actually brought to America by European operators rather than being a later American addition.
Blackjack
Basic strategy in blackjack was first calculated by hand in the 1950s
In 1956, four US Army mathematicians — Roger Baldwin, Wilbert Cantey, Herbert Maisel and James McDermott — published a paper in the Journal of the American Statistical Association presenting mathematically optimal blackjack strategy. They worked it out using desk calculators, a process that took several years. Their work became the foundation for all subsequent blackjack mathematics.
Card counting isn't illegal — but casinos can refuse service
Card counting in blackjack involves tracking the ratio of high to low cards remaining in the shoe to gain a statistical advantage. It requires no devices and uses only mental arithmetic. In the UK, it's entirely legal. However, casinos are private businesses and can ask a player to stop playing blackjack or to leave, which they do when they identify counters.
Slot Machines
The first mechanical slot machine was invented in San Francisco in 1894
Charles Fey developed what is generally credited as the first mechanical slot machine — the Liberty Bell — around 1894–1895 in San Francisco. It had three spinning reels with five symbols (horseshoe, diamond, spade, heart, bell) and paid out automatically for matching symbols. The bell symbol survives in modern slot iconography.
Modern slot machines use random number generators, not mechanical reels
Virtually all contemporary slot machines — physical or online — use a Random Number Generator (RNG): software that produces thousands of random numbers per second. The moment you press spin, the RNG's current output determines the result. The visual spinning reels are a presentation of an already-determined outcome, not the mechanism that decides it.
Return-to-player (RTP) describes long-run averages, not session outcomes
An RTP of 96% means that, theoretically, the game returns 96p for every £1 wagered across a very large number of spins — hundreds of thousands at minimum. In any individual session, actual returns can vary enormously in either direction. RTP is a statistical property of the game's design, not a prediction for a given player in a given session.
All facts on this page are drawn from historical record and published mathematical research. No statistics have been invented or approximated. 18+ · Gamble responsibly · GamStop