A slot is an elongated depression, groove, notch, or slit, especially a narrow opening for receiving or admitting something, such as a coin or a letter. The term derives from the mechanical slot machines that first introduced this type of machine to the public in the 1890s, which used reels with symbols such as diamonds, hearts, horseshoes, and liberty bells to pay out winning combinations.
Slots are a vital component of a machine’s design, and there are many types to choose from. The amount of money paid out depends on the symbols that line up on a payline, which in turn is determined by the random number generator (RNG). A higher RNG means better odds for winning, and vice versa.
Volatility is the amount of variation in a slot’s outcomes, including the frequency and size of wins. When volatility is high, the machine is expected to return more losses than it pays out in winnings over a long period of time. When volatility is low, the machine will return more winnings than it loses, but not enough to offset its operating costs.
A custom slot is a regular expression that maps values in an utterance to specific slots in the bot’s schema. For example, you can create a “location slot” to denote cities in a travel bot. You can add a custom slot by selecting it from the Slots page or by clicking Add Slot Type on the Utterance tab.