A slot is an electronic machine where the player inserts cash or tickets into a designated slot, and then presses a lever to activate the machine. The reels spin and stop, and if the symbols match the ones displayed on the paytable, the player earns credits.

The paytable lists the numbers of credits that a player will receive for matching symbols on a pay line, and also indicates whether any special symbols have been added, such as a Wild symbol or a Bonus. The paytable can be found either on the face of the machine, or in a help menu.

Modern slot machines use microprocessors to assign different probabilities to each symbol on every reel, which is much more efficient than having the odds manually adjusted by a human at regular intervals of perhaps two weeks. This allows casinos to maintain precise control over the odds of the games, allowing for greater jackpots and more exciting games without sacrificing profitability.

In addition to the pay table, a machine should also provide explanations of how the symbols work and explain any special bonuses or features that are part of the game. Typically, there will be a video of the game itself that shows how the reels spin and how to win in various ways on the various paylines.