In casinos, a slot is a place for a coin to drop when the machine is struck or activated. A slot can also refer to a set of reels, the symbols that appear on them, and the paytable that describes the different payouts based on combinations of these symbols. Most slot games have a theme, such as a style, location, or character, and the symbols and bonus features are aligned with this theme.
When the machine is struck or activated, a reel spins and the symbols stop in a pattern determined by the paytable. When a winning combination is achieved, credits are earned based on the paytable. The coins can be inserted into the machine by hand or, in “ticket-in, ticket-out” machines, a paper ticket with a barcode can be scanned to activate the reels and determine whether a prize is won.
The number of possible combinations of symbols on a slot machine is limited by the number of symbols on the reel and the fact that each symbol must occupy only one position in each rotation. To compensate for this limitation, manufacturers weight particular symbols to increase the likelihood that they will appear.
The random number generator (RNG) inside a slot machine generates a sequence of numbers, each of which is recorded by the computer and then used to index into the list of repository items that are contained in the slot. The RNG then selects three of these numbers and uses the internal sequence table to map them to the appropriate stops on the slot reel.