Let's Make a Deal (also known as LMAD) is an American television game show that originated in the United States in 1963. The Big Deal serves as the final segment of the show and offers a chance at a significantly larger prize for a lucky trader. Before the round, the value of the day's Big Deal is announced to the audience. The process for choosing traders (two up to 2003, one since 2009) has remained the same. Starting with the highest winner, the host asks traders if they are willing to trade in everything they have won to that point for a chance to choose one of three numbered doors on the stage.

Source: Wikipedia