A slot (plural slots) is a narrow notch, groove, or opening such as a keyway in machinery or a slit for coins in a vending machine. A slot can also be a position in a series or sequence of events.

In slot games, players place cash or, in “ticket-in, ticket-out” machines, paper tickets with barcodes into a slot on the machine, which activates reels that spin and stop to rearrange symbols to form winning combinations. Most slot games have a theme, and the symbols and bonus features are aligned with that theme. Modern slot machines use microprocessors to assign different probabilities to each symbol on each reel. This allows the manufacturer to make it appear that a particular symbol is so close to appearing on the payline when, in reality, it has much less chance of doing so.

Many online slot games offer a variety of bonus features that can increase a player’s chances of winning. These may include scatter symbols, free spins, jackpots, and wheel spin bonuses. Some of these features are triggered when three or more scattered or wild symbols appear on the reels and offer an additional payout, often with multipliers or access to higher-tier bonus games. Other bonus features are more unique, such as the “hold and spin” bonus patented by slot studio Aristocrat. This feature replaces regular symbols with money awards or jackpot prizes and resets after each spin, providing multiple opportunities to win.