Las Vegas slot machine history

Before Las Vegas: San Francisco bells and the Nevada ban

The machines that would fill Las Vegas were born a few hundred miles west, in San Francisco. Charles Fey’s Liberty Bell, three reels with horseshoes, diamonds, spades, hearts and a bell, set the pattern for the modern slot. Its date is disputed: Wikipedia’s slot machine article places it ‘at some time between 1887 and 1895’, while its Charles Fey article says 1898, and an 1899 Liberty Bell is held in the Nevada State Museum’s Fey Collection. Our Liberty Bell and Charles Fey pages set out both accounts.

Chicago’s Mills Novelty Company then produced its own Liberty Bell in 1907, described by one Wikipedia article as a copy and by another as a collaboration with Fey; see Mills Novelty. By 1908 bell machines were common in cigar stores, barber shops and less respectable places.

Then Nevada shut the door. According to Wikipedia’s Nevada article (opens in a new tab), gambling was outlawed in the state in 1909 as part of a nationwide anti-gambling crusade. Our page on slot machine bans covers that era across the United States.

19 March 1931: the start of Las Vegas slot machine history

Nevada legalised gambling again on 19 March 1931, in a bill signed by Governor Fred B. Balzar. That date is the real beginning of Las Vegas slot machine history: from then on, slot machines could operate openly in licensed Nevada venues while most of the country kept them illegal.

For decades, slots were the side attraction. Table games drew the high rollers; machines were for spouses and small change. The machines themselves were still mechanical descendants of the Liberty Bell, with a pull lever that gave rise to the nickname explained on our one-armed bandit page. The bell symbol and the fruit symbols added by Mills remained on the reels.

Dates for the creation of Nevada’s Gaming Control Board and Gaming Commission are often quoted, but we couldn’t confirm them from the sources we checked, so they are left out here.

Money Honey and the electromechanical hopper

The first big technical leap came from Bally Manufacturing. Its Money Honey is described as the first fully electromechanical slot machine, able to pay out up to 500 coins automatically from a hopper. Bally had shown early electromechanical construction in its 1940 High Hand draw-poker machine.

Two disputes surround Money Honey. Its date is given as 1963 by Wikipedia’s slot machine article and The Paris Review, and as 1964 by Wikipedia’s Bally Manufacturing article (opens in a new tab) and the Las Vegas Advisor (opens in a new tab). And Wikipedia calls its hopper ‘bottomless’, while the Las Vegas Advisor says it was the first machine with a hopper and that bottomless hoppers came later. The Advisor also notes it still used a cranked lever and was played standing.

Why the hopper mattered: earlier machines could pay only small amounts from a coin tube, and larger wins needed an attendant. A hopper holding hundreds of coins allowed bigger automatic payouts, and with them bigger prizes. Our electromechanical slot machines page explains the technology, and Bally covers the company.

1976: the first video slot at the Las Vegas Hilton

In 1976 the Las Vegas-based Fortune Coin Co. developed the first video slot machine, built in Kearny Mesa, California, around a modified 19-inch Sony Trinitron receiver. Its first production units were tested at the Las Vegas Hilton before Nevada approved them. The same year, New Jersey allowed casino gambling in Atlantic City, ending Nevada’s near-monopoly on legal casinos in the US.

In 1978 Fortune Coin and its video technology were bought by the company then called Sircoma, founded by William ‘Si’ Redd in 1975 as A-1 Supply. Sircoma became International Game Technology and went public in 1981. Our first video slot machines page tells that story, and IGT covers the company today.

Players took time to trust a screen instead of spinning metal reels. The breakthrough for video came later with features that physical reels couldn’t show, such as the second-screen bonus round: WMS’s Reel ’Em In of 1996 was the first American video slot with one, after Australia’s Three Bags Full in 1994. See our Australian pokies history.

Virtual reels: how Las Vegas jackpots grew

A physical reel can only carry so many symbols, which limits how rare the top combination can be. Norwegian mathematician Inge Telnaes solved that with US Patent 4,448,419, granted in 1984, in which a random number generator chooses reel stops from a larger set of virtual positions. The patent later passed to IGT and has now run out.

Give each of three reels 256 virtual stops and the machine can produce 16,777,216 different results (256 × 256 × 256). The worked example below shows why that changed jackpots (figures illustrative):

1. You press spin; the RNG has already produced a number for each reel.
2. Each number maps to one of 256 virtual stops.
3. Each virtual stop maps to a physical symbol, with blanks and low symbols given many virtual stops.
4. The motors stop the physical reels on those symbols.
5. The paytable decides whether that combination wins.

This is why a jackpot symbol can appear just above or below the line far more often than it lands on it, and why a near miss tells you nothing. Our guides to the random number generator and reels and symbols explain the mapping in more depth.

Megabucks and the wide-area progressive

IGT’s Megabucks linked machines across many Nevada casinos to a single jackpot that grew with every bet. The Wikipedia progressive jackpot article (opens in a new tab) dates the introduction of progressive jackpots in large casinos to 1986 and records the first Megabucks win, $4,988,842.17, on 1 February 1987.

Treat ‘first progressive slot’ claims for Megabucks with care. One Wikipedia article calls it the first progressive slot machine, while another describes Nevada Megabucks as the first wide-area progressive, with a $1 million base jackpot. The second, narrower claim is the safer one. Our Megabucks page covers it, and the wide-area progressive entry explains how the prize pool is funded.

Stools, slant-tops and paper tickets

Smaller changes shaped the modern Las Vegas slot floor too. The Las Vegas Advisor credits IGT designer Richard Fiore with the first ‘slant-top’ machine designed for a seated player on a stool, sometime in the 1980s or early 1990s, though the writer adds caveats about the claim.

The end of the coin bucket came with ticket-in, ticket-out (TITO). An early trial ran at the Desert Inn under MGM’s ‘Cashless Casino’ consortium with Bally Gaming, IGT and Sigma Games, though the sources don’t date it. On 29 September 2000 IGT announced that its EZ Pay system had completed a field trial at the Fiesta Hotel & Casino in Las Vegas, leading to statewide approval by the Nevada Gaming Control Board, according to Wikipedia’s TITO article (opens in a new tab). How those vouchers are printed, cashed and replayed is covered in what slot machine tickets are.

Las Vegas slot machine history: timeline

Las Vegas slots versus UK slot machines

Las Vegas machines run under Nevada law, which Wikipedia reports sets a 75% minimum payout. Great Britain has no legal minimum that we could find, but it caps every machine by category, as the Gambling Commission’s gaming machine categories (opens in a new tab) show.

If you are a UK visitor heading to Nevada, our guide to Las Vegas slot machines for UK visitors covers what to expect. For machines in British casinos, see casino slot machines.

Las Vegas slot myths

• ‘Casinos loosen machines near the entrance.’ No source we checked supports it, and each spin is random. See loose and tight slot machines.
• ‘A machine that just paid the jackpot won’t pay again for ages.’ Every spin is independent; the RNG doesn’t remember.
• ‘Megabucks was the first progressive ever.’ The safer claim is first wide-area progressive.
• ‘The first slot machine was invented in Las Vegas.’ The early machines came from Brooklyn, San Francisco and Chicago; Las Vegas came later.

Jackpot odds on modern machines are set by design and can be extremely long; read the odds of winning a slot machine jackpot before chasing one.

Las Vegas-style slots online in the UK

Many online slots borrow the look of the Las Vegas strip, but in Great Britain they follow UK rules. The casinos below are licensed here; each offer is for new customers aged 18 or over and has terms.

Coral: deposit, then bet £10 on slots, and 100 free spins follow at 10p each on selected games, usable for seven days, with nothing to wager on winnings; e-wallets such as PayPal and Skrill don’t qualify. Ladbrokes: £10 of slot play earns 50 free spins a day across ten days, a 500-spin maximum at 10p each and no wagering. PlayOJO: put in at least £10 as your first deposit and get 80 spins on Big Bass Bonanza, 10p apiece, with cash winnings and no wagering. One company runs both Coral and Ladbrokes, so its terms may limit you to one welcome offer. Search lobbies for specific games, as availability changes.

Treat any session as the price of entertainment, set limits in advance and never chase losses. Free, confidential support is on 0808 8020 133, and GAMSTOP can block British gambling sites for you.

18+. Gambling should be entertainment that costs money, not a way to make it. Decide a budget before you play: plan a slot budget. Free, confidential help: National Gambling Helpline 0808 8020 133.