What is a Slot?

A narrow notch, groove, or opening, as in a keyway in machinery or a slit for a coin in a vending machine. Also, the position of someone or something in a group, series, sequence, etc. I can slot you in at 2 p.m.

On a slot game, the pay table shows how much you will win if certain symbols line up on the pay line of the machine. The pay table is usually printed on the machine or, in the case of video slots, contained within the help menu.

Unlike the Sittman and Pitt invention, Charles Fey’s slot machine allowed automatic payouts and had three reels instead of one. He also replaced the poker symbols with diamonds, spades, horseshoes, hearts, and liberty bells. Getting three aligned liberty bells earned the highest jackpot, which gave the slot machine its name.

In modern slot machines, microprocessors have increased the number of possible combinations on each reel. But the probability of any particular symbol appearing on a given stop is still based on its relative frequency on the physical reel—a different factor from its probability on the pay table.

A progressive jackpot is a prize pool built up by multiple casinos’ slot machines. The top jackpot on a progressive slot machine may be thousands of dollars or even more than a million, depending on the casino and the type of game. The jackpot can be triggered by a single spin, or it can occur after many spins. The jackpots are usually governed by rules set by the casino.