During the 1980s, slot machine manufacturers started adding electronics to their machines. These machines have a mechanical look, but are controlled by computers instead of gears. They use short digital pulses of electricity to move a motor with great precision.
In the early days of slot machines, the symbols on each reel would only appear once. This allowed players to have a number of combinations. But the odds of losing symbols became disproportionate to the frequency of symbols appearing on the physical reel. Eventually, the symbols increased to 22.
Today, most machines have multiple pay lines. The number of lines played is a matter of preference. Players can play additional horizontal lines above and below the main pay line or diagonal lines running across the reels.
Slots are also used in air traffic control at airports. Each stop on each reel closes a different switch in the electrical system. The pay table is usually listed on the machine face, or in the help menu.
Slots also come with bonus features. These usually are related to the theme of the game. In addition to a payout, players can win a jackpot. Unlike mechanical machines, electrical slot machines are more sophisticated, with flashier light and sound displays.
In addition to the slot-related items, the machine has a pay table, which lists credits when the symbols line up on the pay line. The pay table can be listed in the help menu or in the lower section of the area containing the wheels.