Nine strangers are locked together in a bunker and told they cannot leave until they unanimously choose to award one of them the grand prize. If a contestant leaves the bunker, the amount of the available prize is cut in half.
Votes are cast by each contestant selecting the name of one of the other contestants.
If a vote is not unanimous, something negative happens to the players in order to increase the pressure to reach a unanimous decision. Throughout the course of the game, these were the "punishments" the players received:
The contestants select three random envelopes, each containing a secret about one of them. It is not known whose secrets are being read, and contestants vote to decide which secret is the worst. The holder of that secret is "outcast" from the game, meaning they are no longer eligible to win the money, but that they will remain in the bunker (wearing a special uniform) and continue to vote. Outcast players are also still subject to the rule that if anyone leaves, the amount will be halved. (After Vote 1)
All contestants (including Outcasts) must in turn vote. The contestant who gets the least amount of votes is subsequently made an "outcast" (after Votes 2 & 3)

The contestants are told that every second they can not reach a unanimous decision will cost them. - the prizw will not stop shrinking until either they all agree who wins it, or the Prize goes down to nothing. Meaning either they agree who gets it, or no one does. Before every vote the clock is stopped. If they do not agree the clock is restarted after the end of the vote.

(Concept modified to suit TiBB)