Mathematics – Slot probability function

Can someone please point me in the right direction? I'm working on a slot game. I'm having trouble figuring out how to implement the probability function for. The game has a set of symbols in which you can bet. A symbol is selected when the start button is pressed. If there is a bet on the symbol that is selected, the player earns a value equal to [bet]*[bet multiplier]. The bet multipliers work as follows:

  • If the selected symbol is marked with x3, it overrides the normal multiplier and the winning value is equal to bet * 3 for that symbol.

  • If the selected symbol is Apple, then the winning value is [bet apple]* 5

  • If the selected symbol is BAR, the winning value is the bet in BAR multiplied by the multiplier in the selected BAR symbol (x50 or x100).
  • The other symbols are grouped into 2 groups of 3 and share a multiplier value that is selected at the moment a symbol is selected on the board. E.g. The orange, the lemon and the bell form a group. and share a multiplier of 10, 15 and 20. If the selected symbol is lemon and the selected multiplier is 10, the winning value is equal to [bet lemon]* 10

There is also a lucky symbol that has the following 3 results:

  1. The player loses.
  2. 3 symbols are selected and the winning value is the sum of the bets multiplied by their respective multipliers.
  3. A response is activated and a new symbol is selected (it can not be an answer, but it can be one of the other 2 lucky results)

The player can also double his winnings by choosing between two options [1-6] or [8-13] a number between 1 and 13 is generated and the gains are lost or multiplied by 2.

See the attached images for a better understanding of the game.

What I have a problem with is finding a way to select the turn result and the double function while maintaining a reimbursement percentage of X% that should be valid in many twists / doubles and that can be adjusted manually.

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