US Patent 11676454 Credit-substitution symbol mechanics for random based game outcomes

A credit-substitution symbol mechanic for a gaming device is described. The credit-substitution symbol mechanic randomly triggers an add-substitution symbol feature and randomly determines a number of substitution symbols to add to a first reel to be displayed in a reel area. The credit-substitution symbol mechanic randomly determines a substitution symbol from the number of substitution symbols added to the first reel is a credit-substitution symbol and determines that the credit-substitution symbol is part of a payline. The credit-substitution symbol substitutes as a different symbol type when forming the payline. The credit-substitution symbol mechanic performs a first payout for the payline that pays out a payline award and performs a second payout for the payline that pays out a credit value of the credit-substitution symbol.