What is a Slot?


A slot is a narrow notch, groove or opening, such as one in the head of a screw or a hole for a coin in a vending machine. A slot can also refer to a position within a group, series, sequence or schedule. For example, visitors can book a time slot to visit a museum or other attraction.

In video slot machines, a player inserts cash or, in the case of “ticket-in, ticket-out” machines, a paper ticket with a barcode into a designated slot on the machine. The machine then displays symbols on the reels and, if a combination of symbols matches a paytable payout, the player receives credits according to the paytable. The symbols on a slot machine vary, but classics include fruit, bells and stylized lucky sevens. Some machines offer multiple paylines; others have fixed lines that must be wagered on with every spin.

Psychologists Robert Breen and Marc Zimmerman found that players of video slots reach a debilitating level of involvement with gambling three times as fast as people who play traditional casino games. As a result, many gamblers who play video slots are unable to quit, even when they have lost significant amounts of money.

In aviation, a slot is the time allotted to an airplane for takeoff from a specific airport or point in airspace, as determined by traffic management. It is usually calculated using an aircraft’s computed takeoff time, plus a safety margin of -5/+10 minutes. Central flow management of slots began in Europe over twenty years ago and has produced massive savings in delay and fuel burn.