A slot is a narrow opening, especially one for receiving something, such as a coin or a letter. The word is also used to refer to a position or assignment, as in the phrase “he was given the slot as chief copy editor.” (From The American Heritage(r) Dictionary of the English Language, Fifth Edition.)

In the game of slot machine, a line of symbols on a reel or in a carousel can be matched to earn credits according to the pay table displayed on the machine. On older mechanical machines, this information was printed on a seven-segment display; on video slot machines it may be displayed in stylized text. The pay tables vary among different slot games, but they usually describe the odds of winning a certain combination of symbols.

Often, a slot is marked with an indicator light that flashes to indicate change needed, hand pay requested or a problem with the machine. A slot may also have a credit meter to show the number of credits being played. On some machines, the credit meter may be shown in the carousel with the symbols, while on others it is a separate window.

When a slot is lit, the player inserts cash or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode into a slot and activates a spinning reel. Then, depending on the game’s theme and design, it may return coins or tokens, or award a number of credits based on a winning symbol combination. A 15-coin payout is typical for three-reel slot machines; some modern machines offer 9, 15, 25 or as many as 1024 pay lines.