A slot is a narrow opening, usually for receiving something, such as a coin or letter. Also, a position or assignment: a job at a newspaper; the seat assigned to a new student. See also slit and notch.
In slot machines, the result of a spin is determined by a computer chip that generates random numbers within a massive spectrum. These numbers determine which symbols land and how much the machine pays. This is why it’s important to play one machine at a time: If you pump money into two or more machines, your chances of winning are greatly reduced.
The game’s returns are calibrated in advance to give the casino a certain percentage of the total amount paid into the machine. This is called the “theoretical payout percentage.” To make sure this payout rate is accurate, the games are tested over millions of spins.
Slots are the most popular casino games, in part because they’re simple: put in your money, spin the reels, and hope for a row of identical symbols. But the technology behind them is complicated. To understand how they work, start by reading the explainers that accompany each game. They’re typically printed on small tables or screens and may highlight how much you can win from landing three, four, or five symbols—along with instructions for special features, such as Scatter or Bonus symbols. The tables can also reveal how many paylines each game has, which are the lines that let you win if you line up three or more matching symbols.