A narrow opening or groove, especially one in which something can be inserted. You can fit letters and postcards in a mail slot at the post office. In video games, a slot is the vertical column of symbols that spin after you place your bet and press the spin button (or pull the lever on older machines).

A space or position in which someone or something can fit, such as the chief copy editor’s slot at the newspaper. Linguistics: A position in a construction that can be filled by any of a set of morphemes or morpheme sequences. Compare slit.

In a casino, a slot is a machine that accepts coins or paper bills to activate a game for each spin. Before the 1990s, players dropped coins into slots in live casinos and used bill validators or credit meters to track their wagers, but online slots have blurred the distinction between real cash and virtual credits.

The probability of winning on a slot is always less than the amount wagered, even in the short run. However, you can increase your chances of success by reviewing the rules and features before you play.

Most slot games have a pay table that displays the symbols that appear and their payout values. Some also include special bonus features, such as Wild symbols (which substitute for other symbols to create winning combinations), Scatter symbols that trigger free spins or bonus rounds, and multipliers that multiply your wins.