A slot is a narrow opening, especially one that has been cut or made to receive something, such as a coin.

The word is also used for a machine or device that accepts cash or paper tickets with barcodes for redeeming winnings. Unlike the old mechanical slot machines that use gears to determine the outcome of each spin, modern games are controlled by a computer. A player inserts money or, in ticket-in, ticket-out machines, a paper ticket with a barcode into a designated slot, then activates the machine by pushing a button or lever (either physical or on a touchscreen). The computer generates random numbers that correspond to stops on the reels. If the symbols line up along a payline, the player earns credits based on the game’s payout table. The payouts vary depending on the type and theme of the game, but classic symbols include fruit, bells, and stylized lucky sevens.

Modern slots may offer a variety of bonus features, including free spins, pick-style games, sticky wilds, and re-spins. Rules for these features are generally explained in the slot’s pay table, or information table.

Another important part of a slot’s rules is its payout percentage, which indicates how much of the money a machine takes in will be paid out to players over time. This number is determined by the machine’s program, which has been carefully designed and tested to achieve a particular payback percentage. For example, if a machine has a payout percentage of 90 percent, it will take in 10 percent of all the money deposited into it and give away 90 percent of that amount over time.