The first video slot machines

The idea

Replace three physical reels with a display. With nothing mechanical to limit it, a machine could have any number of symbols and any odds.

The resistance

Players trusted reels they could see. It took years, and regulatory approval, for screens to be accepted.

What followed

Second-screen bonus rounds, five reels, multiple paylines and, in the 1990s, the same games online. After changes to defeat cheating, the machine was approved by Nevada's gaming regulator and went into Las Vegas casinos. IGT bought the company and its technology in 1978.

Elsewhere on the site: UK slot machine categories, PlayOJO slot machines, The cherry symbol and Slot machine near misses.

Virtual reels

The screen was half the change. The other half was mapping random numbers to reel positions in software, which let a machine have odds unrelated to the symbols drawn on its reels. That idea, patented in the 1980s, is what made very large jackpots affordable to offer.

Keep reading: How fruit machines got their fruit, Nudges, The best time to play slot machines and The one-armed bandit.

Slot figures are developers' published defaults, each confirmed against two sources; the version at your casino can differ. UK land-based stake and prize limits and online rule dates were checked against Gambling Commission and licensing authority sources on 6 October 2026. History follows commonly cited accounts. Offer terms dated 5 October 2026. How we check. 18+. Free help: 0808 8020 133 or safer gambling.