A slot (plural slots) is an opening or hole that allows for something to be inserted. Often used in computing to refer to a position that can be filled or used, such as an available time slot for an appointment. See also: slit, slotted disk, window, hole, vacancy.

In a casino, slot is a device that accepts cash or paper tickets with barcodes as payment for credits. Depending on the machine, a player may be able to select several reels that spin and stop in combinations to earn credits according to the pay table displayed on the machine. Symbols vary, but classic symbols include fruit, bells, and stylized lucky sevens. Most slot games have a theme, and bonus features align with the theme.

The main reason that people enjoy playing slots is because they provide a way to relieve negative thoughts and feelings. Unlike other forms of gambling, which use variable-ratio reinforcement schedules to induce arousal, slots provide immediate feedback on monetary gains and losses. The higher the amount won, the more extensive and attention-grabbing the feedback is. Thus, it is not surprising that slots are popular with people who have anxiety or depression (Getty et al., 1996; Abbot & Volberg, 2000).

Casino managers are under tremendous pressure to maximize slot profits. However, they do not want to increase house advantages too much because players can detect these hidden increases in the price of a game, and this can lead them to switch casinos (Dixon et al., 2019).