If Plunge is the winning bid, the bidder's hand must contain at least four doubles and, by bidding Plunge, the bidder relays to his partner that he holds a great hand. The bid is automatically 168, and the bidder cannot lose a single trick. The bidder's partner is required to declare trumps, based on his own hand, and to lead by playing the first tile of the first trick.

When a player bids Plunge, he is gambling that he holds the double in his hand to the trumps and offs that his partner has yet to declare. The bidder takes a huge risk by bidding Plunge. If he is lucky, he and his partner match each other on most of the doubles and offs suits; if not, the consequence of his bid is a huge loss.