A slot is a thin opening or groove in something, such as the one on a casino machine through which coins and/or cards are inserted. It is also used to describe a game of chance, based on spinning reels and paying out credits if certain symbols line up. The games are typically themed and characterized by specific icons, sounds, and bonus features that align with the theme.
The process of playing a slot involves inserting cash or, in ticket-in, ticket-out machines, a paper ticket with barcodes into the designated slots on the machine. The machine is then activated by pressing a lever or button (either physical or on a touchscreen). The digital reels spin and, when the winning combination of symbols appears, the player receives credit based on the paytable.
During the electromechanical days of the first slot machines, the reels were controlled by tilt switches that would make or break circuits when tampered with, and that triggered an alarm. Modern electronic slot machines don’t have those, but any kind of technical fault (door switch in the wrong state, reel motor failure, out of coins) is still considered a “tilt”.
A pay table (also called a payout table or a win table) is an informational table that displays the various possible combinations and their payouts for a given slot. These tables are usually displayed on the game’s help screen or, in older video and online slot games, printed directly on the machine glass.