Twice the Gems

10 free games are triggered by any 3 or more scattered ‘Twice the Gems’. ‘Vault’ substitutes for all symbols except scatters and ‘Key’ and appears on reels 2 and 4 only during the free games. When ‘Vault’ appears, it is held in that position until the completion of the feature. During the free games, ‘Key’ appears on reel 3 only and substitutes for all symbols except scatters and ‘Vault’.  When ‘Key’ appears anywhere on reel 3, all symbols in all positions on that reel are replaced by ‘Key’ with x2 multiplier.  Wherever ‘Key’ appears, it is held in that position for the next 2 free games with x4 and x8 multipliers respectively.  Any 2 or more scattered ‘Twice the Gems’ will trigger an additional 3 free games. If ‘Key’ with x2 appears on the last free game and less than 2 scatters appear, an additional 2 free games are triggered. If ‘Key’ with x4 appears on the last free game and less than 2 scatters appear, an additional 1 free game is triggered.