US Patent 10258869 Lock zone

A gaming machine that includes a game controller to select symbols from the memory, cause the display to display the selected symbols at the display positions, determine if the displayed symbols include a predetermined symbol, and if the predetermined symbol lands on the pay line, in response to the predetermined symbol landing on the pay line, 1) cause the display to animate the first plurality of anticipation states on the pay line, and 2) randomly determine whether to transition the predetermined symbol to the second plurality of free spin states, in response to determining the predetermined symbol transitioning to the second plurality of free spin states, cause the display to animate the second plurality of free spin states on the pay line.