Shari Hudspeth has a game called the dice game. how it works. 11 envelopes in my hand. inside each envelope is a care. some of the cards say "win a prize", some say, "book a show" and one says, "Grand prize"! Tonight the grand prize is...(whatever you have chosen)
If you choose to play, you'll roll the dice and whatever number you roll, i'll give you the corresponding envelope! Now here's the rules. if you "win a prize"...you have to take the prize. If you win the "grand prize you have to take the grand prize. If you win "book a show" you have to book a show!
then after everyone has place (this is option but effective) say "Don't open your envelopes yet. I have another chance for you. if you choose to book a show before you open your envelope, you can have the grand prize for sure, once your show is held! Plus whatever is in your envelope! then go around the room and ask each individual again, would you like to book a show and get the grand prize for sure!
Deal or no Deal is similar. I believe it is similar to the envelope game from Karen Phelps.