One player has won a briefcase full of real money. They're going to have to share some of it if they want to walk away with the cash: but if they can't make a deal, no-one's winning anything. And there's a car waiting outside.

Five players, five prizes. The negotiations should be simple: except that some of those prizes are definitely more valuable than others.

The players can more than treble their money: but only if they all work together. And there's a very different strategy to be tempted by.

This time, the prize money goes to whoever bids the lowest amount of money not chosen by any other player. The prize money will be multiplied by the winning number. Players can cooperate to bid high, or bid low and ensure they win.

There's free money on offer - if the players can all work together. They've got a choice: cooperate to win some money for everyone, or quietly increase their own chances at the expense of everyone else.