A slot machine is a casino game in which the player inserts cash or a ticket for a paper slot and pulls a lever. The machine then spins and stops to rearrange symbols on a set of reels. If two or more matching symbols appear on an activated payline, the player wins a payout.

Multi-line machines have been around for decades, but video slots have become more popular since the 1990s. They allow a player to bet multiple “lines” on the video screen — up, down, sideways or diagonally, each with its own payout potential.

Pay table

A pay table explains how much a player can win, the amount of paylines and the betting requirements for each line. In addition, it lists any jackpots available.

Symbols

Symbols are displayed on the slots’ reels and vary according to the theme of the game. Some classic symbols include fruits, bells, and stylized lucky sevens.

Bonus features

Many slot games have bonus rounds, where the player can receive extra credits for winning combinations of certain symbols. These additional credits can increase the total amount of money a player can win.

Credit meter

In live casinos, the credit meter is a small display on the front of the machine that shows the current balance or number of credits. It also indicates when the machine needs a change, hand-pay is requested, or there is an issue with the reels or door switch.

Tilt switches

Electromechanical slot machines used to have tilt switches, which triggered an alarm if the machine was tilted or otherwise tampered with. Those switches are no longer required, but some modern slot machines still use them to notify players of technical issues with the machine or the door switch.