A narrow depression, perforation, or aperture; especially, one for the reception of a piece fitting or sliding into it. (From Middle English slot, from Old English sleita; compare slit, hoop.) Also, a position or period within a schedule or sequence: I booked my haircut for the 2 p.m. slot.

In a gambling machine, the set of symbols that line up to create a winning combination. These are represented by the reels and slots on a machine’s screen. Today’s machines often have multiple pay lines that run in numerous directions, so slots are referred to more broadly as “paylines.” Some slots also feature specific symbols known as wilds that can substitute for other symbols in winning combinations.

Some slots have progressive jackpots that increase in size every time someone plays the machine. The jackpot may reach a fixed amount or it may reset to zero after a certain number of spins. In either case, the jackpot is not a guaranteed winner and players should only gamble with money they can afford to lose.

When playing a slot, players should always read the pay table before they start spinning. It explains how the game works and what the different combinations of symbols are worth. It also displays any bonus features that the game might have. Many of these bonuses are triggered by words such as ‘progressive’, ‘mega’, or ‘jackpot’ in the title, but they can also appear on the reels themselves.