A narrow notch or opening, as in a keyway or the slit for a coin in a slot machine. Also used: 1. A position in a group, series, or sequence. 2. A time of day when a task is scheduled to be performed. 3. An allocation of space in a flight schedule authorized by an air-traffic control authority. 4. The area in front of an opponent’s goal in ice hockey that affords a favorable vantage for an attacking player.

Modern slot machines are programmed to assign a different probability to each symbol on each reel, which makes the machine appear to pay out more frequently than it actually is. This illusion is further amplified by the use of a large number of different symbols, each with a distinct appearance and corresponding probability.

The popularity of slots is largely due to the fact that they provide a unique form of entertainment. They are designed to capture players’ attention, and many people report that they enjoy playing slots because the intermittent rewards allow them to escape from negative thoughts and experiences. However, these positive effects are likely only a partial explanation for why so many people find slots enjoyable. A more complete explanation might be that the exogenous reining in of attention by a slot machine induces an unusual state for players that Dixon and colleagues have called dark flow, which is an emotional experience that can be highly enjoyable.