A mechanical reel system with alterable reel symbols. Pivoting reel symbol members are provided at predetermined locations about a reel, each member having two, three, or six sides, for example. On each surface, a different symbol (or a blank symbol) is disposed thereon. A transmissive LCD is positioned over the reels, and when the reels display blanks, images are displayed on the LCD over the blanked area(s) during, e.g., a video bonus game played on the LCD. The symbol members can be altered within a game to display a different set of symbols on the reels, or they can be altered to convert the game from one theme to another. In another embodiment, a bellow-like reel strip, which is folded accordion-style, is retracted or extended relative to the periphery of the reel, allowing a symbol set or subset to replace a corresponding symbol (sub)set displayed on the underlying reel.