This is my first time watching this. Basically, it's like this - choose one briefcase out of 26 (22 in Britain). Spend the rest of your time eliminating the rest of them, from $1 Mil to 1 cent. (in the States; amount depends on where you are) Every time a certain number of briefcases are opened, the banker calls offering you a load of money to quit the game. At that time, it's "Deal or No Deal?" No deal, the game rolls on; deal, you're on your way. Pretty simple, but exciting.
http://en.wikipedia.org/wiki/Deal_or_No_Deal (Wikipedia article)
http://www.nbc.com/Deal_or_No_Deal/(NBC area)
http://en.wikipedia.org/wiki/Deal_or_No_Deal (Wikipedia article)
http://www.nbc.com/Deal_or_No_Deal/(NBC area)