Patent ID: 7481708

Claim:
A gaming device controlled by a processor, said gaming device comprising: a primary game controlled by the processor and operable upon a wager by a player; and a free spin mode controlled by the processor and that is initiated if a triggering event occurs in a play of the primary game, wherein said free spin mode includes a number of free spins of a plurality of reels without an additional wager by the player, wherein said number is undetermined until a free spin mode terminating event is triggered, said reels including a plurality of symbols, said plurality of symbols including at least one locking symbol and at least one designated symbol, wherein for each free spin, an award is provided to the player for any winning symbol combinations which occur in said free spin, wherein said free spin mode terminating event is triggered if at least one of the locking symbols is generated on at least one reel in a first group of said reels and at least one of the designated symbols is generated in a second different group of said reels, wherein in the free spin mode terminating event the player is provided with a predetermined number of additional free spins prior to termination of the free spin mode, said predetermined number being at least one, and wherein at least one locking symbol is held stationary for each said additional free spin.