With the highly rated Million Dollar Mission episodes of Deal or No Deal having concluded Monday, NBC is brewing another stunt for its stalwart game show: an around-the-world tour.

For the May sweep, the show will visit local versions of the show in Estonia, the Philippines and South Africa.

Host Howie Mandel and contestants from the U.S. will play the game according to the foreign set's rules. And yes, the Deal girls will be locals. (Some 40 versions of Deal are produced worldwide.)

We're constantly trying to come up with new ideas to keep the show fresh, to tweak and make the gameplay different, executive producer Scott St. John said. It's been a fun internal thing when we watch clips from the foreign versions, so we decided we're going to explore the way they do it.

The plan comes at the close of the 19 Million Dollar Mission episodes that have aired this season and re-energized the show's ratings. NBC's alternative programming chief Craig Plestis said he plans to repeat the stunt in the fall and make the episodes a staple of the series. (No official Deal renewal has been announced, but Plestis said another season can be assumed.)

In Deal, contestants open 26 briefcases containing values ranging from 1 cent to $1 million, gradually paring down the board and constantly shifting the odds of how much they'll take home. Nobody has won the $1 million.

For the Million Dollar Mission (or MDM, as they call it at the network), every time a contestant failed to win the top prize, producers added $1 million case to the lineup, increasing the likelihood of somebody winning the top prize. On Monday night, a California couple had the board stocked with 13 of the $1 million cases, giving them a 50-50 chance of winning, but they still came up short.

The MDM temporarily turned Deal into a serialized program -- much like Jeopardy! during Ken Jennings' famed ratings-boosting winning streak in 2004.

Yet MDM wasn't always a ratings driver. When NBC first tried the MDM last year, it was during a shorter period and resulted in only a modest performance increase. In September, NBC tried again, for six episodes. MDM episodes were on par, or even underperformed, regular editions.

Since the start of the year, and aided by less competition because of the writers strike, the stunt took off. Deal has become NBC's top-rated series and has been the highest-rated show on the past five Monday nights. Last week's MDM episode reached about 16.18 million viewers -- the show's best score in nearly a year.

The only downside to creating so much excitement around a series of special episodes is that regular episodes start to seem, well, not so special.

Two days after that season-high rating, a non-MDM episode slid to 8.9 million viewers. That episode was a Wednesday edition, when Deal airs against Fox's behemoth American Idol.

So why stop the stunt?

One reason might have to do with the MDM episodes paying out increasingly higher cash prizes, on average, than regular episodes.

(NBC is) ultimately responsible for the prize money, so maybe they had more a calendar in mind for how long it goes, St. John said.

Plestis said the rising average payouts were not a factor. We really didn't calculate out what it's going to cost us more for the cash prizes than the other games, he said.

What's important, added St. John, is you show that they get up to a 50-50 shot at winning $1 million -- that justifies the mission. We are legitimately giving people the most incredible odds. Certain versions of the show may be more exciting to some people, but it's always going to be 'win it all, or lose it all.'

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