My gameshow would be a different spin on the recent phenomena on BBC here in the UK - The Traitors
The premise of Traitors is for a group of people to earn money through tasks, only for allocated 'traitors' to remain hidden within the group and slowly 'murder' the other contestants to ultimately steal the prize money at the end. It has rounds where each contestant then votes to banish a member of the group who they think is the traitor, ultimately improving their chances of winning the money at the end with the other remaining contestants.
My version of this would be called 'The Saboteurs'.
The premise remains similar: a group of contestants aiming to complete tasks to earn money towards a total end prize fund. The tasks here though would be more challenging in this show, as the aim of the saboteurs is to intentionally lose the team money so it is then placed in the saboteurs own prize fund they could win at the end.
As mentioned, the tasks would be very diffuclt with large sums of money attached to reflect this. The difficult also then makes any attempts by the saboteurs to throw the attempts of the group seem more genuine and just 'unlucky'.
The saboteurs prize pot would remain hidden, with the contestants only knowing the total amount lost as to not give away who the saboteurs are and how much they have stolen. The task difficulty would mean that any member of the group could cause the prize money to be lost so as to make it seem anyone could be the saboteurs.
The contestants would again then be able to vote on who they believe the saboteurs are, increasing their chance of successfully completing tasks and adding to the end prize fund.
The twist is the saboteurs will not be able to win any of the 'normal' prize fund, even if they stay in the show until the very end. The only money they can win is their own saboteurs prize fund, should they make it to the end.
If saboteurs remain at the end, they would win their prize fund but the other contestants would win nothing, adding extra pressure and incentive to remove the correct contestants from the game!