Even in Nevada, slot machines were merely a curiosity, with even the largest casino containing no more than a few hundred machines. They were there to entertain the browsers, while the serious gambling was conducted at the tables.
A couple of things happened in the 1960s and 1970s that changed the attitudes of both the casino executives and the players. Electro-mechanical machines were developed by pinball-machine builder Bally Manufacturing which permitted many more payouts than the mechanical machines could accommodate. And the Bally machines came complete with an enlarged “hopper”, or coin-storage unit, that could
hold up to 2,500 coins. In addition, the Bally machines could accept more than one coin at a time, which allowed the players to insert up to five coins on one pull of the handle. Bally also developed many machines for Europe through its Bally Wulff subsidiary, including many wall-mounted units
popular in Germany.

Sound effects, special lighting, music and more frequent payouts drew more and more players to the slot machines. Players could choose from three, four, and five-reel machines and, in 1980, Bally engineered a group of advanced machines that could. be linked together to create a giant jackpot.
Ironically, this development would fuel the growth of Bally’s chief competitor, IGT, which developed the “life-changing” million dollar jackpots now commonplace in systems like “Megabucks”, “Quartermania” and “Dollars Deluxe”.

Today, there are dozens of slot-machine manufacturers around the world, including Australia’s Aristocrat, Japan’s Konami (each with major subsidiaries in the US), Europe’s Novomatic, and many companies based in the US. Slot machines are often designed for specific markets. In Australia, Aristocrat produces video-slot machines that include intricate graphics and complicated payouts for a very sophisticated slot player. In Japan, pachinko and pachisuro parlours reward players with prizes rather than cash. American players vary according to the area in which they play. In Las Vegas and Atlantic City, mature slot players turn more frequently to video poker, where they feel they have
some control over their wins or losses. In other, newer, jurisdictions, the simpler the machine, the better. The fact remains that slot machines are becoming more and more popular, and slot manufacturers are producing more attractive machines to entice increasingly selective players.