Reel Strip
The ordered list of symbols that makes up a single reel and defines how often each symbol can appear.
Definition
A reel strip is the full sequence of symbol positions that a reel is built from, only a few of which are visible in the window at any time. The strip's length and the count of each symbol on it determine how frequently that symbol shows up, so it is a primary input to the game's odds. Modern slots use virtual reel strips inside software rather than physical bands, and different strips are often used for the base game and features. Understanding reel strips is essential because they, more than the visible layout, set the true probability of each outcome and support the house edge.
Worked example
A reel strip of 50 positions might contain 12 low-value symbols, only 2 of a high-value symbol, and 1 wild. Because that high-value symbol occupies just 2 of 50 stops, it appears rarely, which is why lining several up pays so much.
Why it matters
For a learner, reel strips reveal that the true odds live in the symbol layout behind the scenes, not in what is on screen. For a professional, designing reel strips is the core craft of slot math and directly determines RTP and volatility.