Part I: Games & Gaming · Slot Machines & Electronic Gaming

Reel

Slot Mechanics

The vertical spinning column in a slot machine that displays symbols. In mechanical slot machines, reels are physical cylindrical components with symbols printed or affixed to their surface, driven by stepper motors. In video slots, reels are simulated graphical representations rendered on a display screen. Each reel has a defined number of “stops” — positions where it can come to rest. The number of stops, combined with the symbol distribution across those stops, is a fundamental determinant of the game’s mathematical profile and is specified on the PAR sheet.

In practice

Modern mechanical-reel machines almost universally employ virtual reel mapping, where the physical reel has 22 stops but the virtual reel may have 64-128+ stops.

One entry from the Casino Industry Glossary — 1,157 terms written for surveillance, compliance and operations professionals rather than for players. Definitions describe industry usage; where a term carries a regulatory meaning, verify against the instrument that governs your jurisdiction.