What is a Slot?


A slot is an opening in the wing or tail of an airplane used for a control device. A slot in a computer might refer to an expansion slot, such as an ISA, PCI or AGP (accelerated graphics port) slots. Alternatively, a slot may be a position in a group, series or sequence. In gambling, a slot might refer to the number of available combinations of symbols on the reels.

Most slot games are designed around a theme and feature a pay line that must be hit to win. The symbols vary with each machine, but classic icons include stylized lucky sevens and fruit. A player inserts cash or, on “ticket-in, ticket-out” machines, a paper ticket with a barcode, into the machine, then presses a spin button (either physical or virtual) to activate the reels. The reels then stop to display a random combination of symbols and award credits based on the paytable.

In the past, mechanical slot machines used a limited number of symbols that could be displayed on each reel. With the advent of electronic controls, manufacturers began to weight certain symbols more heavily than others, allowing them to appear more frequently on a single reel and increasing jackpot size.

Modern slot machines use a random number generator (RNG) to produce thousands of unique numbers each second, each associated with a different symbol. When the spin button is pressed, the RNG selects three of these numbers, and the computer matches them to symbols on the reels. Each spin is independent, and no previous or upcoming play affects its outcome.