Dice Game 20!

There were times where merchants would play a game of commerce. Here, the challenge was to determine whether making certain moves in the market would be profitable for them or their competition. While many were prone to dice games, 20! was invented to demonstrate the ebbs and flows that commerce straddles. It is a game of chance whereby shrewdness is the victor.
20! is a game where players must balance trade to reach an ideal economy, which is 20. The players rool a 1d20 and keep the amount secret. Then, the first round occurs. The players roll either a 1d4, 1d6, 1d8, or a 1d12. The player must either subtract or add the value to their d20. Then the players ante. The players then choose a dice and roll again. The next round, one of the players can match the bet in the pool and call for a contested pot. At this point, the opponent may agree without adding anything to the pot and reveal their hand. The winner with the highest d20 wins (after adding or subtracting the newly rolled dice). One of the players can match the bet in the pool and call for a contested pot. At this point, the opponent may agree without adding anything to the pot and reveal their hand. The winner with the highest d20 wins (after adding or subtracting the newly rolled dice). If the contested pot is not accepted, the players continue to repeat rounds until the fifth round. At any point of the rounds, a play may withdraw and abadon the money put in the pot. At the end of five rounds, the d20's are revealed. The highest d20 wins. If, at any point, a player achieves 20, the player can either reveal the dice or continue rolling.
Notes: If a player adds or subtracts a dice, the resulting value must be a value on the d20. If not, that player immediately loses. If a judge is not adjudicating: Each round the players announce if they have busted. If they say that they have not and have, they roll a deception dice contested by an insight check. If caught, the player immediately loses and the opponent wins. This may end with a confrontation. The player can also act nervous to force the opponent to reveal the players dice (resulting in a fool's posture) that causes the opponent to immediately lose. This is a performance check contested by the opponent's insight. If deceived, the opponent immediately loses and becomes agitated. The player can also use sleight of hand when adding the dice, resulting in a change in the value of the dice that is one side away (disadvantage for d4's). This is contested by the players perception. If caught, the opponent moves down one attitude level (friendly->neutral->hostile). In a casino, there is always an adjudicant and cheating is always caught as each die roll is recorded (in the case of loaded dice.)