A slot is a position or time in which something happens. For example, you can book a flight on a specific day or time in advance by scheduling a slot. Similarly, you can be assigned a slot at work or school. A slot is also a term used to describe a slot in a computer system, such as an ISA, PCI, or AGP slot.

In slot machines, players insert cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode into a slot or opening on the machine. Then, the machine activates reels that stop to rearrange symbols and award credits based on the pay table. Symbols vary according to the theme of the game, with classic symbols including fruits, bells, and stylized lucky sevens.

On video slots, the pay tables are often listed above and below the area containing the wheels, or in a help menu. On older machines, they are sometimes printed on the face of the machine or, if the machine is electronic, displayed on a monitor. Psychologists Robert Breen and Marc Zimmerman have found that people who play video slot machines reach a debilitating level of involvement with gambling three times more rapidly than those who play traditional casino games, even if they previously gambled without problems. The reason may be that the microprocessors in modern slot machines allow them to manipulate odds and payouts more than traditional mechanical machines. Some players let their paranoia get the better of them and believe that a back room staff is pulling the strings and determining who wins and loses.