Following this, a "banker", seated in a surveillance room above the studio floor, phones the host with an "offer" - a dollar amount he is willing to make for the briefcase the contestant chose at the start of the game. Essentially, the offer is an average of all the cash amounts on the monitor that haven't been yet eliminated - the more low amounts that are eliminated, the higher the offer. The host informs the contestant of the offer - which is posted in large numerals on the projection monitor - and then, after a bit of mathematical banter, the host pops the all-important question to the contestant: "Deal or No Deal?" If the contestant accepts the Deal, he/she wins the value of the offer and the game ends. If not, the contest must open five more briefcases before the next offer is made. If the contestant passes on the Deal at that point, then he/she must open four more cases, then three more, then two more, until in the later points in the game, there is an offer issued after one briefcase is selected.
The tension increases with every round of selections because in many cases, a contestant chooses a case with a large dollar amount, eliminating the possibility of winning that prize. Also adding to the drama - the contestant has three to four other guests (loved ones or friends) on the show to help him/her decide whether or not to take a Deal, usually introduced after the second round of briefcase selections. So there is an emotional aspect to "Deal" as well, one the large studio audience gets pumped up for.
Once the contestant has accepted a Deal, the host has the contestant theoretically play out the rest of the briefcase selections ("Let's see what you would have done...") and then reveals the contents of the briefcase that the contestant chose at the start of the game.
Overall, "Deal or No Deal" offers the best odds for winning $1 million on national TV - 1 in 26. But as host Howie Mandel states at the beginning of each show, the game is a combination of "luck, guts, and a great sense of timing." Part of Mandel's opening spiel: "One million dollars as the top prize. No crazy stunts to perform, no trivia questions to answer. In fact, there's only one question you need to know how to answer, the only question that counts. Deal or No Deal?" At the time of this writing, "Deal or No Deal" was introduced by NBC as a "stripped" broadcast (same time for five consecutive weeknights), airing between 8pm and 9pm Eastern Time. The show's initial ratings for the first two nights were great news for NBC; they handily won their Monday and Tuesday time slots.
Part of the entertainment value of "Deal or No Deal" is watching the contestants agonize over whether to accept a Deal or press their luck; a knowledge (or appreciation) of probability helps a lot, and screen graphics are occasionally shown to help viewers do the numbers (Example: "Kyle has a 25% chance his case contains at least $300,000"). The exchanges between the contestants and their guests are often very funny. Host Howie Mandel, better known for his goofball stand-up comedy and appearances on "The Tonight Show With Jay Leno", is an affable host, not overpowering the show. He has "a great sense of timing" himself, and sets up cliffhangers before each commercial (sending the audience into frustrated groans of anticipation).
And for anyone that doesn't believe there's a play-along element to the show, you get caught up in the moment, screaming at the TV, "Take the deal, you bonehead!" Most NBC affiliates also participated in the "Lucky Case" home game, in which viewers could win $10,000 based on their selection of one of the 26 cases.
Considering "Deal or No Deal" requires no intellectual knowledge (other than, perhaps, a little statistical analysis) nor mastery of a game (such as "Wheel of Fortune" or GSN's "Lingo") it is a surprisingly entertaining show. At the time of this writing, over 30 other countries had their own versions of the show.