A slot is a narrow opening for receiving or admitting something, such as a coin or letter. The term may also refer to the position or job occupied by a particular person or thing, such as “the slot” in management training or “the slot on the broadcasting schedule.” See also groove (def 6), notch (def 7), slit (def 3), track (def 1), and trail.
In a slot machine, players insert cash or, in the case of “ticket-in, ticket-out” machines, paper tickets with barcodes, which are then read by the machine’s reels to determine winners. Symbols on the reels vary by theme, but classic symbols include fruits and bells. The machine then pays out credits according to a pay table, and the player can either take the payout or gamble it on a double-or-nothing side game.
Slot makers design games with specific mathematical models that define the odds of winning. A mathematical model may be simple or complex, and it usually combines probability theory with computer programming. Some machines have a single model, while others use many different models that depend on the denomination of the machine and the number of coins wagered.
A key concept in slot design is volatility, or risk. A low-volatility game offers regular but smaller wins, while a high-volatility game has few but larger wins. In some states, the volatility of a machine is determined by law.
